Agilent Technologies E8257D/67D & E8663D PSG Signal Generators User’s Guide Agilent Technologies
Notices © Agilent Technologies, Inc. 2006-2014 Manual Warranty No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Technologies, Inc. as governed by United States and international copyright laws. The material contained in this manual is provided “as is,” and is subject to being changed, without notice, in future editions.
Contents 1. Signal Generator Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Signal Generator Models and Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 E8257D PSG Analog Signal Generator Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 E8267D PSG Vector Signal Generator Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents 25. Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 26. Contrast Decrease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 27. Contrast Increase. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 28. Local . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents 16. GPIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 17. 10 MHz EFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 18. ALC HOLD (Serial Prefixes >=US4722/MY4722) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 19. AUXILIARY INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents Configuring a Continuous Wave RF Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Configuring a Swept RF Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Extending the Frequency Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Modulating a Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents Waveform Marker Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97 Accessing Marker Utilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101 Viewing Waveform Segment Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102 1. Clearing Marker Points from a Waveform Segment . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents Creating a User Flatness Correction Array with a mm–Wave Source Module . . . . . . . . . . . . . . 140 Using the Option 521 Detector Calibration (Option 521) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Running the Option 521 Detector Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Restoring the Factory Flatness Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents 6. Custom Arb Waveform Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159 Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159 Working with Predefined Setups (Modes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159 Selecting a Custom ARB Setup or a Custom Digital Modulation State . . . . . . . . . . .
Contents Working with Phase Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 To Set Phase Polarity to Normal or Inverted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 Working with Differential Data Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 Understanding Differential Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents Arb Waveform Generator AWGN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .237 Real Time I/Q Baseband AWGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .238 12. Peripheral Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239 N5102A Digital Signal Interface Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents xii
Documentation Overview Installation Guide User’s Guide Programming Guide SCPI Reference • • • • Safety Information • • • • • • • • • • • • Signal Generator Overview • • • • • • Getting Started with Remote Operation • • • • • • • Using this Guide Getting Started Operation Verification Regulatory Information Basic Operation Basic Digital Operation Optimizing Performance Analog Modulation Custom Arb Waveform Generator Custom Real Time I/Q Baseband Multitone Waveform Generator Two- Tone Waveform Ge
Service Guide Key Reference xiv • • • • • Troubleshooting • Key function description Replaceable Parts Assembly Replacement Post- Repair Procedures Safety and Regulatory Information
1 Signal Generator Overview In the following sections, this chapter describes the models, options, and features available for Agilent E8257D/67D and E8663D PSG signal generators. The modes of operation, front panel user interface, and front and rear panel connectors are also described.
Signal Generator Overview Signal Generator Models and Features E8257D PSG Analog Signal Generator Features The E8257D PSG includes the following standard features: • a source module interface that is compatible with Agilent 83550 Series millimeter–wave source modules for frequency extension up to 110 GHz and Oleson Microwave Labs (OML) AG–Series millimeter–wave modules for frequency extensions up to 325 GHz • automatic leveling control (ALC) on and off modes; power calibration in ALC–off mode is available,
Signal Generator Overview Signal Generator Models and Features Option UNX—ultra low phase noise performance Option UNY—enhanced ultra low phase noise performance Option UNT—AM, FM, phase modulation, and LF output • open–loop or closed–loop AM • dc–synthesized FM to 10 MHz rates; maximum deviation depends on the carrier frequency • external modulation inputs for AM, FM, and M • simultaneous modulation configurations (except: FM with M or Linear AM with Exponential AM) • dual function generators that inclu
Signal Generator Overview Signal Generator Models and Features • high output power (optional for the E8257D & E8663D) • step attenuator (optional for the E8257D) The E8267D PSG offers the same options as the E8257D PSG, plus the following: Option 003—PSG digital output connectivity with N5102A Option 004—PSG digital input connectivity with N5102A Option 0051 (Discontinued)—6 GB internal hard drive Option 0092—8 GB removable compact flash drive Option 015 (Discontinued)—single–ended wideband external I/Q in
Signal Generator Overview Signal Generator Models and Features internal gated, and external pulse; internal triggered, internal doublet, and internal gated require an external trigger source — adjustable pulse rate — adjustable pulse period — adjustable pulse width (150 ns minimum) — adjustable pulse delay — selectable external pulse triggering: positive or negative The E8663D PSG also offers the following optional features: NOTE To provide analog frequency sweeps and for optimum swept scalar me
Signal Generator Overview Options • simultaneous modulation configurations (except: FM with M or Linear AM with Exponential AM) • dual function generators that include the following: — 50–ohm low–frequency output, 0 to 3 Vp, available through the LF output — selectable waveforms: sine, dual–sine, swept–sine, triangle, positive ramp, negative ramp, square, uniform noise, Gaussian noise, and dc — adjustable frequency modulation rates — selectable triggering in list and step sweep modes: free run (aut
Signal Generator Overview Modes of Operation 6. In the “Documents and Downloads” table, click the link in the “Upgrade Assistant Software” column for the E8257D/67D or E8663D PSG to download the PSG/ESG Upgrade Assistant. 7. In the File Download window, select Run. 8. In the Welcome window, click OK and follow the on–screen instructions. 9. At the desktop shortcut prompt, click Yes. 10. Once the utility downloads, close the browser and double–click the PSG/ESG Upgrade Assistant icon on the desktop. 11.
Signal Generator Overview Modes of Operation Analog Modulation In this mode, the signal generator modulates a CW signal with an analog signal. The analog modulation types available depend on the installed options. Option UNT provides amplitude, frequency, and phase modulations. Some of these modulations can be used together. Options UNU and UNW provide standard and narrow pulse modulation capability, respectively. Option UNU is standard on the E8663D. Option 1SM provides improved Exponential (Log) AM mode.
Signal Generator Overview Front Panel Front Panel This section describes each item on the PSG front panel. Figure 0- 1 shows an E8267D front panel, which includes all items available on the E8257D and E8663D. Figure 1-1 Standard E8267D Front Panel Diagram 37 2 5 4 3 6 7 8 9 10 11 12 1 36 35 13 14 34 15 33 16 18 32 30 31 29 28 27 26 25 24 23 22 21 20 19 17 E8267D only E8257N, 8257D, and E8267D 1. 2. 3. 4. 5. 6. 7. 8. 9.
Signal Generator Overview Front Panel 1. Display The LCD screen provides information on the current function. Information can include status indicators, frequency and amplitude settings, and error messages. Softkeys labels are located on the right–hand side of the display. For more detail on the front panel display, see “Front Panel Display” on page 16. 2. Softkeys Softkeys activate the displayed function to the left of each key. 3.
Signal Generator Overview Front Panel 8. Trigger This key initiates an immediate trigger event for a function such as a list, step, or ramp sweep (Option 007 only). Before this hardkey can be used to initiate a trigger event, the trigger mode must be set to Trigger Key. For example: press the Sweep/List hardkey, then one of the following sequences of softkeys: • More (1 of 2) > Sweep Trigger > Trigger Key • More (1 of 2) > Point Trigger > Trigger Key 9.
Signal Generator Overview Front Panel 12. EXT 2 INPUT This female BNC input connector (functional only with Options UNT, UNU, or UNW or on the E8663D) accepts a 1 Vp signal for AM, FM, and M. With AM, FM, or M, 1 Vp produces the indicated deviation or depth. When ac–coupled inputs are selected for AM, FM, or M and the peak input voltage differs from 1 Vp by more than 3 percent, the HI/LO annunciators light on the display.
Signal Generator Overview Front Panel 18. RF OUTPUT This connector outputs RF and microwave signals. The nominal output impedance is 50 ohms. The reverse–power damage levels are 0 Vdc, 0.5 watts nominal. On signal generators with Option 1EM, this connector is located on the rear panel. The connector type varies according to frequency option. 19.
Signal Generator Overview Front Panel 25. Return Pressing this hardkey displays the previous softkey menu. It enables you to step back through the menus until you reach the first menu you selected. 26. Contrast Decrease Pressing this hardkey causes the display background to darken. 27. Contrast Increase Pressing this hardkey causes the display background to lighten. 28. Local Pressing this hardkey deactivates remote operation and returns the signal generator to front–panel control. 29.
Signal Generator Overview Front Panel On signal generators with Option 1EM, this connector is located on the rear panel. 34. DATA CLOCK This female BNC input connector is CMOS compatible and accepts an externally supplied data–clock input signal to synchronize serial data for use with the internal baseband generator (Option 601/602). The expected input is a 3.3 V CMOS bit clock signal (which is also TTL compatible) where the rising edge is aligned with the beginning data bit.
Signal Generator Overview Front Panel Display Front Panel Display Figure 0- 2 shows the various regions of the PSG display. This section describes each region. Figure 1-2 1. 2. 3. 4. 16 Front Panel Display Diagram Active Entry Area Frequency Area Annunciators Digital Modulation Annunciators 5. 6. 7. 8.
Signal Generator Overview Front Panel Display 1. Active Entry Area The current active function is shown in this area. For example, if frequency is the active function, the current frequency setting will be displayed here. If the current active function has an increment value associated with it, that value is also displayed. 2. Frequency Area The current frequency setting is shown in this portion of the display.
Signal Generator Overview Front Panel Display EXT REF This annunciator appears when an external frequency reference is applied. FM This annunciator (Option UNT only) appears when frequency modulation is turned on. If phase modulation is turned on, the M annunciator will replace FM. I/Q This annunciator (E8267D only) appears when I/Q modulation is turned on.
Signal Generator Overview Front Panel Display transmitting information over the GPIB, RS–232, or VXI–11 LAN interface. UNLEVEL This annunciator appears when the signal generator is unable to maintain the correct output level. The UNLEVEL annunciator is not necessarily an indication of instrument failure. Unleveled conditions can occur during normal operation. A second annunciator, ALC OFF, will appear in the same position when the ALC circuit is disabled.
Signal Generator Overview Rear Panel Rear Panel This section describes each item on the PSG rear panel. Four consecutive drawings show the standard and Option 1EM rear panels for the E8267D, E8257D, and the E8663D. (Option 1EM moves all front panel connectors to the real panel.) Figure 1-3 1. EVENT 1 2. EVENT 2 3. PATTERN TRIG IN 4. 5. 6. 7. 8. BURST GATE IN AUXILIARY I/O DIGITAL BUS Q OUT I OUT 9. WIDEBAND I INPUTS 10. I–bar OUT 20 Standard E8267D Rear Panel 11. WIDEBAND Q INPUTS 12.
Signal Generator Overview Rear Panel Figure 1-4 E8267D Option 1EM Rear Panel 1. EVENT 1 2. EVENT 2 3. PATTERN TRIG IN 4. BURST GATE IN 5. AUXILIARY I/O 6. DIGITAL BUS 7. Q OUT 8. I OUT 9. WIDEBAND I INPUTS 10. I–bar OUT 11. WIDEBAND Q INPUTS 12. COH CARRIER (Serial Prefixes >=US4646/MY4646) 13. 1 GHz REF OUT (Serial Prefixes >=US4646/MY4646) 14. Q–bar OUT 15. AC Power Receptacle Chapter 1 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. GPIB 31. RF OUT 10 MHz EFC 32.
Signal Generator Overview Rear Panel Figure 1-5 Standard E8257D and E8663D Rear Panel 29 5. AUXILIARY I/O 12. COH CARRIER (Serial Prefixes >=US4646/MY4646) 13. 1 GHz REF OUT (Serial Prefixes >=US4646/MY4646) 15. AC Power Receptacle 16. GPIB 17. 10 MHz EFC 22 22 44 30 28 27 26 25 23 21 13 19 17 16 20 15 19. AUXILIARY INTERFACE 20. 10 MHz IN 26. SWEEP OUT 27. TRIGGER OUT 21. LAN 28. TRIGGER IN 22. 10 MHz OUT 23. STOP SWEEP IN/OUT 25. Z–AXIS BLANK/MKRS 29. SOURCE SETTLED 30.
Signal Generator Overview Rear Panel Figure 1-6 31 E8257D and E8663D Option 1EM Rear Panel 32 33 43 35 34 29 13. 1 GHz REF OUT (Serial Prefixes >=US4646/MY4646) 15. AC Power Receptacle 16. GPIB 17. 10 MHz EFC 19. AUXILIARY INTERFACE 20. 10 MHz IN 21. LAN Chapter 1 28 36 27 37 22 30 44 26 25 23 21 20 13 19 17 16 15 22. 10 MHz OUT 32. EXT 1 23. 25. 26. 27. 28. 29. 31. 33. EXT 2 34. PULSE SYNC OUT 35. PULSE VIDEO OUT 36. PULSE/TRIG GATE INPUT 37. ALC INPUT 43. LF OUT 44.
Signal Generator Overview Rear Panel 1. EVENT 1 This female BNC connector is used with an internal baseband generator (Option 601/602). On signal generators without Option 601/602, this female BNC connector is non–functional. In real–time mode, the EVENT 1 connector outputs a pattern or frame synchronization pulse for triggering or gating external equipment. It may be set to start at the beginning of a pattern, frame, or timeslot and is adjustable to within ± one timeslot with one bit resolution.
Signal Generator Overview Rear Panel 5. AUXILIARY I/O This female 37–pin connector is active only on instruments with an internal baseband generator (Option 601/602); on signal generators without Option 601/602, this connector is non–functional. This connector provides access to the inputs and outputs described in the following figure. Figure 1-7 View looking into rear panel connector Auxiliary I/O Connector (Female 37–Pin) EVENT 3: Used with an internal baseband generator.
Signal Generator Overview Rear Panel 6. DIGITAL BUS This is a proprietary bus used for Agilent Baseband Studio products, which require an E8267D with Options 003/004 and 601/602. This connector is not operational for general–purpose customer use. Signals are present only when a Baseband Studio option is installed (for details, refer to http://www.agilent.com/find/basebandstudio).
Signal Generator Overview Rear Panel I–bar OUT is used in conjunction with I OUT to provide a balanced baseband stimulus. Balanced signals are signals present in two separate conductors that are symmetrical relative to ground and are opposite in polarity (180 degrees out of phase). The nominal output impedance of the I–bar OUT connector is 50 ohms, dc–coupled. 11.
Signal Generator Overview Rear Panel output the complement of the quadrature–phase component of an external I/Q modulation that has been fed into the Q input connector. Q–bar OUT is used in conjunction with Q OUT to provide a balanced baseband stimulus. Balanced signals are signals present in two separate conductors that are symmetrical relative to ground and are opposite in polarity (180 degrees out of phase). The nominal output impedance of the Q–bar OUT connector is 50 ohms, dc–coupled. 15.
Signal Generator Overview Rear Panel 19. AUXILIARY INTERFACE This 9–pin D–subminiature female connector is an RS–232 serial port that can be used for serial communication and Master–Slave source synchronization.
Signal Generator Overview Rear Panel 22. 10 MHz OUT This female BNC connector outputs a nominal signal level of > 4 dBm and has an output impedance of 50 ohms. The accuracy is determined by the timebase used. 23. STOP SWEEP IN/OUT This female BNC connector (Option 007 only) provides an open–collector, TTL–compatible input/output signal that is used during ramp sweep operation. It provides low–level (nominally 0 V) output during sweep retrace and band–cross intervals.
Signal Generator Overview Rear Panel 28. TRIGGER IN This female BNC connector accepts a 3.3V CMOS signal, which is used for point–to–point triggering in manual sweep mode, or in a low frequency (LF output) or analog (AM, FM, and M) external sweep trigger setup. Triggering can occur on either the positive or negative edge of the signal start. The damage level is 4 V or 10 V. The nominal input impedance for this connector is approximately 4.2 kohms. 29.
Signal Generator Overview Rear Panel MOD SENSE Source module sense. A 1 mA current is injected on this line by the mm source module to indicate its presence. This signal always equals 0V. L MOD RF OFF Low = RF off. Source module RF is turned off. EXT LVL RET Source module external leveling return. EXT LVL Source module external leveling input, from the mm source module. 0.5V/GHz Internal 0.5 V/GHz to the mm source module. –15V Power Supply. Range is –14.25 to –15.90V. 15V Power Supply.
Signal Generator Overview Rear Panel 34. PULSE SYNC OUT This female BNC output connector (functional only with Options UNU or UNW) outputs a synchronizing TTL–compatible pulse signal that is nominally 50 ns wide during internal and triggered pulse modulation. The nominal source impedance is 50 ohms. On signal generators without Option 1EM, this connector is located on the front panel. 35.
Signal Generator Overview Rear Panel 40. SYMBOL SYNC This female BNC input connector (E8267D only) is CMOS–compatible and accepts an externally supplied symbol synchronization signal for use with the internal baseband generator (Option 601/602). The expected input is a 3.3 V CMOS bit clock signal (which is also TTL compatible). SYMBOL SYNC might occur once per symbol or be a single one–bit–wide pulse that is used to synchronize the first bit of the first symbol. The maximum clock rate is 50 MHz.
Signal Generator Overview Rear Panel 44. Flash Drive (Serial Prefixes >=US4829/SG4829/MY4829 (E8267D) and >=US4928/SG4928/MY4928 (E8257D)) The removable compact flash drive is not hot swappable – always turn the power off to the instrument when removing or inserting the memory. Use only Agilent provided or certified compact flash cards. This flash drive (Options 008 and 009 only) outputs data to a removable flash card.
Signal Generator Overview Rear Panel 36 Chapter 1
2 Basic Operation In the following sections, this chapter describes operations common to all Agilent PSG signal generators: • “Using Table Editors” on page 38 • “Using the User- Defined RF Output Power Limit (Option 1EU, or 521 only)” on page 40 • “Configuring a Continuous Wave RF Output” on page 42 • “Configuring a Swept RF Output” on page 45 • “Using Ramp Sweep (Option 007)” on page 49 • “Extending the Frequency Range” on page 59 • “Turning On a Modulation Format” on page 59 • “Applying a Modulation For
Basic Operation Using Table Editors Using Table Editors Table editors simplify configuration tasks, such as creating a list sweep. This section provides information to familiarize you with basic table editor functionality using the List Mode Values table editor as an example. Press Preset > Sweep/List > Configure List Sweep. The signal generator displays the List Mode Values table editor, as shown below.
Basic Operation Using Table Editors Table Editor Softkeys The following table editor softkeys are used to load, navigate, modify, and store table item values.
Basic Operation Using the User-Defined RF Output Power Limit (Option 1EU, or 521 only) Using the User-Defined RF Output Power Limit (Option 1EU, or 521 only) Selecting a User-Defined RF Output Power Limit To protect external components and instruments against damage the PSG has a user- defined RF output limit (see Figure 2- 2). The factory default value of the RF output limit is set to 25 dBm and the RF adjusting limit value softkey is not available (see Figure 2- 2).
Basic Operation Using the User-Defined RF Output Power Limit (Option 1EU, or 521 only) Figure 2-2 User-Defined RF Output Limit Softkey Menu Amplitude > More > More This softkey is only active when the RF Output Limit softkey is set to “Adjust”.
Basic Operation Configuring the RF Output Configuring the RF Output This section provides information on how to create continuous wave and swept RF (page 45) outputs. It also has information on using a mm–Wave source module to extend the signal generator’s frequency range (page 59).
Basic Operation Configuring the RF Output 7. The down arrow decreases the frequency by the increment value set in the previous step. Practice stepping the frequency up and down in 1 MHz increments. You can also adjust the RF output frequency using the knob. As long as frequency is the active function (the frequency is displayed in the active entry area), the knob will increase and decrease the RF output frequency. 8. Use the knob to adjust the frequency back to 700 MHz.
Basic Operation Configuring the RF Output Setting the Low Pass Filter (Options 1EH and 521) CAUTION Option 1EH can degrade power below 2 GHz. Use Option 1EH when improved harmonics are desired but a degradation of power below 2 GHz is acceptable. Refer to the Data Sheet for details. Options 1EH and 521 improves the harmonic distortion performance for carrier frequencies ranging from 10 MHz to 2 GHz. Refer to the Data Sheet for specifications on these options. 1. Press Preset. Default Off 2.
Basic Operation Configuring the RF Output The AMPLITUDE area displays 10.00 dB, which is the power output by the hardware (–20 dBm plus 10 dBm) minus the reference power (20 dBm). The power at the RF OUTPUT connector changes to 10 dBm. 7. Enter a 10 dB offset: Press Ampl Offset > 10 > dB. The AMPLITUDE area displays 20.00 dB, which is the power output by the hardware (10 dBm) minus the reference power (20 dBm) plus the offset (10 dB). The OFFS indicator activates.
Basic Operation Configuring the RF Output The signal generator provides a softkey, Sweep Retrace Off On, that lets you configure single sweep behavior. When sweep retrace is on, the signal generator will retrace the sweep to the first point of the sweep. If the sweep retrace is off, the sweep will stop and remain on the last point in the sweep.
Basic Operation Configuring the RF Output This changes the start frequency of the step sweep to 500 MHz. 6. Press Freq Stop > 600 > MHz. This changes the stop frequency of the step sweep to 600 MHz. 7. Press Ampl Start > –20 > dBm. This changes the amplitude level for the start of the step sweep. 8. Press Ampl Stop > 0 > dBm. This changes the amplitude level for the end of the step sweep. 9. Press # Points > 9 > Enter. This sets the number of sweep points to nine. 10. Press Step Dwell > 500 > msec.
Basic Operation Configuring the RF Output editing several points in the List Mode Values table. For information on using tables, see “Using Table Editors” on page 38. 1. Press Sweep Repeat Single Cont. This toggles the sweep repeat from continuous to single. The SWEEP annunciator is turned off. The sweep will not occur until it is triggered. 2. Press Sweep Type List Step. This toggles the sweep type from step to list. 3. Press Configure List Sweep.
Basic Operation Configuring the RF Output The frequency for point 8 is still active. 10. Press 590 > MHz. 11. Press Insert Item > –2.5 > dBm. This inserts a new power value at point 8 and shifts down the original power values for points 8 and 9 by one row. 12. Highlight the dwell time for point 9, then press Insert Item. A duplicate of the highlighted dwell time is inserted for point 9, shifting the existing value down to complete the entry for point 10. To Configure a Single List Sweep 1.
Basic Operation Configuring the RF Output Using Basic Ramp Sweep Functions This procedure demonstrates the following tasks (each task builds on the previous task): • “Configuring a Frequency Sweep” on page 50 • “Using Markers” on page 52 • “Adjusting Sweep Time” on page 54 • “Using Alternate Sweep” on page 55 • “Configuring an Amplitude Sweep” on page 56 Configuring a Frequency Sweep 1. Set up the equipment as shown in Figure 2- 3.
Basic Operation Configuring the RF Output mode enables the instruments to work as a system. 4. Press Utility > GPIB/RS–232 LAN to view the PSG’s GPIB address under the GPIB Address softkey. If you want to change it, press GPIB Address and change the value. 5. On the 8757D, press LOCAL > SWEEPER and check the GPIB address. If it does not match that of the PSG, change the value. 6. Preset either instrument. Presetting one of the instruments should automatically preset the other as well.
Basic Operation Configuring the RF Output Figure 2-4 Bandpass Filter Response on 8757D Using Markers 1. Press Markers. This opens a table editor and associated marker control softkeys. You can use up to 10 different markers, labeled 0 through 9. 2. Press Marker Freq and select a frequency value within the range of your sweep. In the table editor, notice how the state for marker 0 automatically turns on. The marker also appears on the 8757D display. 3.
Basic Operation Configuring the RF Output Refer to Figure 2- 5. Figure 2-5 Marker Table Editor 5. Move the cursor back to marker 1 and press Marker Freq. Turn the front panel knob while observing marker 1 on the 8757D. On the 8757D, notice that the displayed amplitude and frequency values for marker 1 are relative to marker 0 as the marker moves along the trace. Refer to Figure 2- 6.
Basic Operation Configuring the RF Output Figure 2-6 Delta Markers on 8757D 6. Press Turn Off Markers. All active markers turn off. Refer to the Agilent PSG Signal Generators Key Reference for information on other marker softkey functions. Adjusting Sweep Time 1. Press Sweep/List. This opens a menu of sweep control softkeys and displays a status screen summarizing all the current sweep settings. 2. Press Configure Ramp/Step Sweep.
Basic Operation Configuring the RF Output 4. Press Sweep Time to Auto. The sweep time returns to its fastest allowable setting. NOTE When using an 8757D network analyzer in manual sweep mode, you must activate the signal generator’s Manual Mode before using the Manual Freq softkey to control the sweep. Press Sweep/List > More (2 of 3) > Manual Mode On. Using Alternate Sweep 1. Press the Save hardkey. This opens the table editor and softkey menu for saving instrument states.
Basic Operation Configuring the RF Output Figure 2-7 Alternating Sweeps on 8757D Configuring an Amplitude Sweep 1. Press Return > Sweep > Off. This turns off both the current sweep and the alternate sweep from the previous task. The current CW settings now control the RF output. 2. Press Configure Ramp/Step Sweep. 3. Using the Ampl Start and Ampl Stop softkeys, set an amplitude range to be swept. 4. Press Return > Sweep > Ampl.
Basic Operation Configuring the RF Output 1. Set up the equipment as shown in Figure 2- 8. Use a 9–pin, D–subminiature, male RS–232 cable with the pin configuration shown in Figure 2- 9 to connect the auxiliary interfaces of the two PSGs. You can also order the cable (part number 8120–8806) from Agilent Technologies. By connecting the master PSG’s 10 MHz reference standard to the slave PSG’s 10 MHz reference input, the master’s timebase supplies the frequency reference for both PSGs. 2.
Basic Operation Configuring the RF Output Figure 2-8 Master/Slave Equipment Setup Figure 2-9 RS–232 Pin Configuration 58 Chapter 2
Basic Operation Modulating a Signal Extending the Frequency Range You can extend the signal generator frequency range using an Agilent 83550 series millimeter–wave source module or other manufacturer’s mm–source module. For information on using the signal generator with a millimeter–wave source module, refer to “Using Agilent Millimeter- Wave Source Modules” on page 272. Modulating a Signal This section describes how to turn on a modulation format, and how to apply it to the RF output.
Basic Operation Modulating a Signal Figure 2-10 Example of AM Modulation Format Off and On First AM Menu Modulation format is off Active Modulation Format Annunciator Modulation format is on Applying a Modulation Format to the RF Output The carrier signal is modulated when the Mod On/Off key is set to On, and an individual modulation format is active. When the Mod On/Off key is set to Off, the MOD OFF annunciator appears on the display.
Basic Operation Using Data Storage Functions Figure 2-11 Carrier Signal Modulation Status Mod Set to On—Carrier is Modulated AM Modulation Format is Active Mod Set to Off—Carrier is not Modulated AM Modulation Format is Active Mod Set to On—Carrier is not Modulated No Active Modulation Format Using Data Storage Functions This section explains how to use the two forms of signal generator data storage: the memory catalog and the instrument state register.
Basic Operation Using Data Storage Functions Table 2-1 Memory Catalog File Types and Associated Data (Continued) ARB Catalog Types (E8267D PSG with Option 601/602 only) user created files – Waveform Catalog Types: WFM1 (waveform file), NVARB Catalog Types: NVWFM (non–volatile, ARB waveform file), NVMKR (non–volatile, ARB waveform marker file), Seq (ARB sequence file), MTONE (ARB multitone file), DMOD (ARB digital modulation file), MDMOD (ARB multicarrier digital modulation file) Modulation Catalog
Basic Operation Using Data Storage Functions 4. Press Catalog Type > All. The “Catalog of All Files” is displayed. For a complete list of file types, refer to Table 2- 1 on page 61. Using the Instrument State Registers The instrument state register is a section of memory divided into 10 sequences (numbered 0 through 9) with each sequence consisting of 100 registers (numbered 00 through 99).
Basic Operation Using Data Storage Functions This saves this instrument state in sequence 1, register 01 of the instrument state register. 5. Press Add Comment to Seq[1] Reg[01]. This enables you to add a descriptive comment to sequence 1 register 01. 6. Using the alphanumeric softkeys or the knob, enter a comment and press Enter. 7. Press Edit Comment In Seq[1] Reg[01]. If you wish, you can now change the descriptive comment for sequence 1 register 01.
Basic Operation Using Security Functions 3. Press Select Seq and enter the sequence number containing the registers you want to delete. 4. Press Delete all Regs in Seq[n]. This deletes all registers in the selected sequence. Deleting All Sequences CAUTION Be sure you want to delete the contents of all registers and all sequences in the instrument state register. 1. Press Preset. 2. Press the Recall or Save hardkey. Notice that the Select Seq softkey shows the last sequence that you used. 3.
Basic Operation Using Security Functions Main Memory (SDRAM) Data Retained When Powered Off? Memory Type and Size Writable During Normal Operation? Table 2-2 Base Instrument Memory Yes No firmware operating memory operating system (not user) CPU board, not battery backed.
Basic Operation Using Security Functions Calibration Backup Memory (Flash) Data Retained When Powered Off? Memory Type and Size Writable During Normal Operation? Table 2-2 Base Instrument Memory (Continued) No Yes Purpose/Contents Data Input Method Location in Instrument and Remarks factory calibration/configuration data backup factory or service only motherboard factory or service only all RF boards, baseband generator, and motherboard memory is managed by CPU, not user CPU board, not
Basic Operation Using Security Functions Buffer Memory (SRAM) No Data Retained When Powered Off? Memory Type and Size Writable During Normal Operation? Table 2-3 Baseband Generator Memory (Options 601 and 602) (Continued) No Purpose/Contents Data Input Method Remarks support buffer memory for ARB and real–time applications normal user operation This memory is used during normal baseband generator operation. It is not directly accessible by the user. Not battery backed.
Basic Operation Using Security Functions CAUTION The removable compact flash drive is not hot swappable – always turn the power off to the instrument when removing or inserting the memory. Use only Agilent provided or certified compact flash cards.
Basic Operation Using Security Functions Removing Sensitive Data from PSG Memory When moving the PSG from a secure development environment, you can remove any classified proprietary information stored in the instrument. This section describes several security functions you can use to remove sensitive data from your instrument.
Basic Operation Using Security Functions DRAM/SDRAM Follow the Department of Defence (DoD) manual’s requirements. The instrument must be powered off to purge the memory contents. The instrument must remain powered off in a secure location for 3 minutes. Hard Disk All addressable locations are overwritten with a single character and then a random character. (This is insufficient for top secret data, according to DoD standards. For top secret data, the hard drive must be removed and destroyed.
Basic Operation Using Security Functions Setting the Secure Mode Level 1. Press Utility > Memory Catalog > More (1 of 2) > Security > Security Level. 2.
Basic Operation Using Security Functions instrument will be repaired and calibrated. If the instrument is still under warranty, you will not be charged for the new hard disk. or • Keep the hard disk and send the instrument to a repair facility. When the instrument is returned, reinstall the hard disk. Flash Drive (Option 008 and 009 only) Either • Discard the flash memory card. Indicate on the repair order that the flash memory was removed and request a new memory card.
Basic Operation Enabling Options Enabling Options You can retrofit your signal generator after purchase to add new capabilities. Some new optional features are implemented in hardware that you must install. Some options are implemented in software, but require the presence of optional hardware in the instrument. This example shows you how to enable software options. Enabling a Software Option A license key (provided on the license key certificate) is required to enable each software option. 1.
Basic Operation Using the Web Server c. Verify that you want to reconfigure the signal generator with the new option: Proceed With Reconfiguration > Confirm Change The instrument enables the option and reboots. Using the Web Server You can communicate with the signal generator using the Web Server. This service uses TCP/IP (Transmission Control Protocol/Internet Protocol) to communicate with the signal generator over the internet.
Basic Operation Using the Web Server 6. Press the Enter key on the computer’s keyboard. The web browser will display the signal generator’s homepage as shown below in Figure 2- 13. This web page displays information about the signal generator and provides access to Agilent’s website.
Basic Operation Using the Web Server 7. Click the Signal Generator Web Control menu button on the left of the page. A new web page will be displayed as shown below in Figure 2- 14. Figure 2-14 Web Page Front Panel This web page remotely accesses all signal generator functions and operations. Use the mouse pointer to click on the signal generator’s hardkeys and softkeys. The results of each mouse click selection will be displayed on the web page.
Basic Operation Using the Web Server 78 Chapter 2
3 Basic Digital Operation This chapter provides information on the functions and features available for the E8267D PSG vector signal generator with Option 601 or 602.
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Custom Arb Waveform Generator The signal generator’s Arb Waveform Generator mode is designed for out–of–channel test applications. This mode can be used to generate data formats that simulate random communication traffic and can be used as a stimulus for component testing. Other capabilities of the Arb Waveform Generator mode include: configuring single or multicarrier signals. Up to 100 carriers can be configured.
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Marker settings and routing functions (page 96) — Polarity — ALC hold — RF blanking • High crest mode (only in the dual ARB player) • Modulator attenuation • Modulator filter • I/Q output filter (used when routing signals to the rear panel I/Q outputs) • Other instrument optimization settings (for files generated by the PSG) that cannot be set by the user.
Basic Digital Operation Arbitrary (ARB) Waveform File Headers the active modulation, you must modify the default settings before you save the header information with the waveform file (see “Modifying Header Information in a Modulation Format” on page 82). NOTE Each time an ARB modulation format is turned on, a new temporary waveform file (AUTOGEN_WAVEFORM) and file header are generated, overwriting the previous temporary file and file header.
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Figure 3-2 Custom Digital Modulation Default Header Display Lets you enter/edit the Description field Clears the Saved Header Settings column to the default settings Saves the Current Inst. Settings column to the Saved Header Settings column Current signal generator settings Note: Page 1 Parameters that are inactive (such as Runtime Scaling) can be set only in the dual ARB player. Page 2 Default Header Settings 2.
Basic Digital Operation Arbitrary (ARB) Waveform File Headers 3. Return to the ARB Setup menu: Press Return. In the ARB Setup menu (shown in Figure 3- 3), you can change the current instrument settings. Figure 3- 3 also shows the softkey paths used in steps four through nine. 4. Set the ARB sample clock to 5 MHz: Press ARB Sample Clock > 5 > MHz. 5. Set the modulator attenuation to 15 dB: Press More (1 of 2) > Modulator Atten n.nn dB Manual Auto to Manual > 15 > dB. 6.
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Figure 3-3 ARB Setup Softkey Menu and Marker Utilities Dual ARB Player softkey (it does not appear in the ARB formats) Chapter 3 85
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Figure 3-4 Differing Values between Header and Current Setting Columns Values differ between the two columns Page 1 Values differ between the two columns Page 2 Figure 3-5 Saved File Header Changes Page 1 Page 2 86 Chapter 3
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Storing Header Information for a Dual ARB Player Waveform Sequence When you create a waveform sequence (described on page 93), the PSG automatically creates a default file header, which takes priority over the headers for the waveform segments that compose the waveform sequence. During a waveform sequence playback, the waveform segment headers are ignored (except to verify that all required options are installed).
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Viewing Header Information with the Dual ARB Player Off One of the differences between a modulation format and the dual ARB player is that even when the dual ARB player is off, you can view a file header. You cannot, however, modify the displayed file header unless the dual ARB player is on, and the displayed header is selected for playback. With the dual ARB player off, perform the following steps. 1. Select a waveform: a.
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Viewing Header Information for a Different Waveform File While a waveform is playing in the dual ARB player, you can view the header information of a different waveform file, but you can modify the header information only for the waveform that is currently playing. When you select another waveform file, the header editing softkeys are grayed–out (see Figure 3- 6). This task guides you through the available viewing choices. 1.
Basic Digital Operation Arbitrary (ARB) Waveform File Headers Playing a Waveform File that Contains a Header After a waveform file (AUTOGEN_WAVEFORM) is generated in a modulation format and the format is turned off, the file becomes accessible to and can only be played back by the dual ARB player. This is true for downloaded waveform files (downloading files is described in the Agilent Signal Generators Programming Guide).
Basic Digital Operation Using the Dual ARB Waveform Player Using the Dual ARB Waveform Player The dual arbitrary (ARB) waveform player is used to create, edit, and play waveform files. There are two types of waveform files: segments and sequences. A segment is a waveform file that is created using one of the signal generator’s pre–defined ARB formats. A sequence can be described as several segments strung together to create one waveform file.
Basic Digital Operation Using the Dual ARB Waveform Player Creating Waveform Segments There are two ways to provide waveform segments for use by the waveform sequencer. You can either download a waveform via the remote interface, or generate a waveform using one of the ARB modulation formats. For information on downloading waveforms via the remote interface, see the Agilent Signal Generators Programming Guide. A waveform sequence is made up of segments but can also contain other sequences.
Basic Digital Operation Using the Dual ARB Waveform Player 2. Create the first waveform segment: a. b. c. d. Press Mode > Dual ARB > Waveform Segments > Load Store to Store. Highlight the default segment AUTOGEN_WAVEFORM. Press Rename Segment > Editing Keys > Clear Text. Enter a file name (for example, TTONE), and press Enter > Store Segment To NVWFM Memory. This renames the waveform segment, and stores a copy in non volatile memory. 3. Generate the second waveform: a.
Basic Digital Operation Using the Dual ARB Waveform Player Playing a Waveform This procedure applies to playing either a waveform segment or a waveform sequence. This example plays the waveform sequence created in the previous procedure. 1. Select a waveform sequence: a. Press Mode > Dual ARB > Select Waveform. b. Highlight a waveform sequence (for this example, TTONE+MTONE) from the Sequence column of the Select Waveform catalog, and press Select Waveform.
Basic Digital Operation Using the Dual ARB Waveform Player Adding Real–Time Noise to a Dual ARB Waveform (E8267D with Option 403) The signal generator with option 403 can apply AWGN (additive white gaussian noise) to a carrier in real time while the modulating waveform file is being played by the Dual ARB waveform player. The AWGN can be configured using front panel softkeys.
Basic Digital Operation Using Waveform Markers Storing Waveform Segments to Non–volatile Memory 1. Press Mode > Dual ARB > Waveform Segments. 2. If necessary, press Load Store to Store. 3. Press Store All To NVWFM Memory. Copies of all WFM1 waveform segment files have been stored in non–volatile memory as NVWFM files. To store files individually, highlight the file and press Store Segment To NVWFM Memory. Loading Waveform Segments from Non–volatile Memory 1.
Basic Digital Operation Using Waveform Markers There are three basic steps to using waveform markers: “1. Clearing Marker Points from a Waveform Segment” on page 103 “2. Setting Marker Points in a Waveform Segment” on page 104 “3.
Basic Digital Operation Using Waveform Markers Marker Point Edit Requirements Before you can modify a waveform segment’s marker points, the segment must reside in volatile memory (see “Loading Waveform Segments from Non–volatile Memory” on page 96). In the dual ARB player, you can modify a waveform segment’s marker points without playing the waveform, or while playing the waveform in an ARB modulation format.
Basic Digital Operation Using Waveform Markers Positive Polarity CAUTION Chapter 3 Incorrect ALC sampling can create a sudden unleveled condition that may create a spike in the RF output, potentially damaging a DUT or connected instrument. To prevent this condition, ensure that you set markers to let the ALC sample over an amplitude that accounts for the higher power levels encountered within the signal.
Basic Digital Operation Using Waveform Markers Example of Correct Use Waveform: 1022 points Marker range: 95–97 Marker polarity: Positive This example shows a marker set to sample the waveform’s area of highest amplitude. Note that the marker is set well before the waveform’s area of lowest amplitude. This takes into account the response difference between the marker and the waveform signal.
Basic Digital Operation Using Waveform Markers Example of Incorrect Use Waveform: 1022 points Marker range: 110–1022 Marker polarity: Negative This figure shows that a negative polarity marker goes low during the marker on points; the marker signal goes high during the off points. The ALC samples the waveform during the off marker points.
Basic Digital Operation Using Waveform Markers When using an ARB format other than Dual ARB, you must turn on the format to enable the Set Markers softkey. NOTE Most of the procedures in this section begin at the Marker Utilities softkey menu. Viewing Waveform Segment Markers Markers are applied to waveform segments. Use the following steps to view the markers set for a segment (this example uses the factory–supplied segment, SINE_TEST_WFM). 1. In the Marker Utilities menu (page 101), press Set Markers.
Basic Digital Operation Using Waveform Markers Select a segment The Set Marker display The display below shows the I and Q components of the waveform, and the marker points set in a factory–supplied segment. First sample point shown on display These softkeys change the range of waveform sample points shown on the marker display. Marker points on first sample point Each press of the softkey changes the sample range by approximately a factor of two 1.
Basic Digital Operation Using Waveform Markers 4. For the selected marker number, remove all marker points in the selected segment: Press Set Marker Off All Points. 5. Repeat from Step 3 for any remaining marker points that you want to remove. Clearing a Range of Marker Points The following example uses a waveform with marker points (Marker 1) set across points 1020. This makes it easy to see the affected marker points.
Basic Digital Operation Using Waveform Markers 3. Highlight the desired marker number: Press Marker 1 2 3 4 4. Set the first sample point in the range (in this example, 10): Press Set Marker On Range Of Points > First Mkr Point > 10 > Enter. 5. Set the last marker point in the range to a value less than or equal to the number of points in the waveform, and greater than or equal to the first marker point (in this example, 20): Press Last Mkr Point > 20 > Enter. 6. Press Apply To Waveform > Return.
Basic Digital Operation Using Waveform Markers 1. Remove any existing marker points (page 103). 2. In the Marker Utilities menu (page 101), press Set Markers. 3. Highlight the desired waveform segment. In ARB formats there is only one file (AUTOGEN_WAVEFORM) and it is already highlighted. 4. Highlight the desired marker number: Press Marker 1 2 3 4 5. Set the first sample point in the range (in this example, 5): Press Set Marker On Range Of Points > First Mkr Point > 5 > Enter. 6.
Basic Digital Operation Using Waveform Markers 2. Toggle the markers as desired: a. Highlight the first waveform segment. b. Press Enable/Disable Markers. c. As desired, press Toggle Marker 1, Toggle Marker 2, Toggle Marker 3, and Toggle Marker 4. Toggling a marker that has no marker points (page 104) has no effect on the auxiliary outputs.
Basic Digital Operation Using Waveform Markers The markers are enabled or disabled per your selections, and the changes have been saved to the selected sequence file. Sequence Marker Column This entry shows that only marker 3 is enabled for this segment. Viewing a Marker Pulse When a waveform plays (page 94), you can detect a set and enabled marker’s pulse at the rear panel event connector that corresponds to that marker number.
Basic Digital Operation Using Waveform Markers RF Output Marker pulse on the Event 1 signal. Using the RF Blanking Marker Function While you can set a marker function (described as Marker Routing on the softkey label) either before or after setting the marker points (page 104), setting a marker function before you set marker points may change the RF output. RF Blanking includes ALC hold (described on page 98, note Caution regarding unleveled power).
Basic Digital Operation Using Waveform Markers Marker Polarity = Positive RF Signal When marker polarity is positive (the default setting), the RF output is blanked during the off maker points. 3.3V 0V Marker Point 1 Segment 180 200 Marker Polarity = Negative RF Signal When marker polarity is negative, the RF output is blanked during the on maker points 3.
Basic Digital Operation Triggering Waveforms Setting Marker Polarity Setting a negative marker polarity inverts the marker signal. 1. In the Marker Utilities menu (page 101), press Marker Polarity. 2. Select the marker polarity as desired for each marker number. Default Marker Polarity = Positive Set each marker polarity independently. See Also: “Saving Marker Polarity and Routing Settings” on page 98. As shown on page 109: Positive Polarity: On marker points are high (3.3V).
Basic Digital Operation Triggering Waveforms • Polarity determines the state of the trigger to which the waveform responds (used only with an external trigger source); you can set either negative, or positive. Source The Trigger hardkey A command sent through the rear panel GPIB, LAN, or Auxiliary (RS–232) interface An external trigger signal applied to either the PATTERN TRIG IN connector, or the PATT TRIG IN 2 pin on the AUXILIARY I/O connector (connector locations are shown in Figure 1-3 on page 20).
Basic Digital Operation Triggering Waveforms • Segment Advance (Dual ARB only) causes a segment in a sequence to require a trigger to play. The trigger source controls how play moves from segment to segment (example on page 116). A trigger received during the last segment loops play to the first segment in the sequence.
Basic Digital Operation Triggering Waveforms Setting the Polarity of an External Trigger Gated Mode The selections available with the gate active parameter refer to the low and high states of an external trigger signal. For example, when you select High, the active state occurs during the high of the trigger signal.
Basic Digital Operation Triggering Waveforms 3. Configure the carrier signal output: • Set the desired frequency. • Set the desired amplitude. • Turn on the RF output. 4. Select a waveform for playback (sequence or segment): a. Preset the signal generator. b. Press Mode > Dual ARB > Select Waveform. c. Highlight a waveform file (for this example, SINE_TEST_WFM). d. Press Select Waveform. 5. Select the waveform trigger method: a. Press Trigger > Gated. b.
Basic Digital Operation Triggering Waveforms Modulating Waveform RF Output Externally Applied Gating Signal Gate Active = High NOTE In the real–time Custom mode, the behavior is reversed: when the gating signal is high, you see the modulated waveform. Using Segment Advance Triggering Segment advance triggering enables you to control the segment playback within a waveform sequence. The following example uses a waveform sequence that has two segments.
Basic Digital Operation Using Waveform Clipping 5. Generate the waveform sequence: Press Return > Return > ARB Off On to On. 6. Trigger the first waveform segment to begin playing repeatedly: Press the Trigger hardkey. 7. (Optional) Monitor the current waveform: Connect the output of the signal generator to the input of an oscilloscope, and configure the oscilloscope so that you can see the output of the signal generator. 8. Trigger the second segment: Press the Trigger hardkey.
Basic Digital Operation Using Waveform Clipping Figure 3-10 Multiple Channel Summing The I and Q waveforms combine in the I/Q modulator to create an RF waveform. The magnitude of the RF envelope is determined by the equation in a positive value. , where the squaring of I and Q always results As shown in Figure 3- 11, simultaneous positive and negative peaks in the I and Q waveforms do not cancel each other, but combine to create an even greater peak.
Basic Digital Operation Using Waveform Clipping Figure 3-11 Combining the I and Q Waveforms How Peaks Cause Spectral Regrowth Because of the relative infrequency of high power peaks, a waveform will have a high peak–to–average power ratio (see Figure 3- 12). Because a transmitter’s power amplifier gain is set to provide a specific average power, high peaks can cause the power amplifier to move toward saturation. This causes intermodulation distortion, which generates spectral regrowth.
Basic Digital Operation Using Waveform Clipping Figure 3-12 Peak–to–Average Power Spectral regrowth is a range of frequencies that develops on each side of the carrier (similar to sidebands) and extends into the adjacent frequency bands (see Figure 3- 13). Consequently, spectral regrowth interferes with communication in the adjacent bands. Clipping can provide a solution to this problem.
Basic Digital Operation Using Waveform Clipping appears as a rectangle in the vector representation. With either method, the objective is to clip the waveform to a level that effectively reduces spectral regrowth, but does not compromise the integrity of the signal. Figure 3- 16 on page 123 uses two complementary cumulative distribution plots to show the reduction in peak–to–average power that occurs after applying circular clipping to a waveform.
Basic Digital Operation Using Waveform Clipping Figure 3-15 122 Rectangular Clipping Chapter 3
Basic Digital Operation Using Waveform Clipping Figure 3-16 Reduction of Peak–to–Average Power Configuring Circular Clipping This procedure shows you how to configure circular clipping. The circular setting clips the composite I/Q data (I and Q data are clipped equally). For more information about circular clipping, refer to “How Clipping Reduces Peak–to–Average Power” on page 120. 1. Press Preset > Mode > Custom > Arb Waveform Generator > Digital Modulation Off On to On.
Basic Digital Operation Using Waveform Clipping 2. Press Mode > Dual ARB > Select Waveform and ensure that AUTOGEN_WAVEFORM is highlighted on the display. AUTOGEN_WAVEFORM is the default name assigned to the waveform you generated in the previous step. 3. Press Select Waveform. This selects the waveform and returns you to the previous softkey menu. 4. Press ARB Off On to On. The Dual Arb player must be turned on to display the CCDF plot in the following steps. 5.
Basic Digital Operation Using Waveform Scaling 11. Press Waveform Statistics > CCDF Plot and observe the waveform’s curve. Notice the reduction in peak–to–average power, relative to the previous plot, after applying clipping. Using Waveform Scaling Waveform scaling is used to eliminate DAC over–range errors. The PSG provides two methods of waveform scaling.
Basic Digital Operation Using Waveform Scaling Figure 3-18 Waveform Overshoot How Scaling Eliminates DAC Over–Range Errors Scaling reduces or shrinks a baseband waveform’s amplitude while maintaining its basic shape and characteristics, such as peak–to–average power ratio.
Basic Digital Operation Using Waveform Scaling Although scaling maintains the basic shape of the waveform, too much scaling can compromise its integrity because the bit resolution can be so low that the waveform becomes corrupted with quantization noise. Maximum accuracy and optimum dynamic range are achieved by scaling the waveform just enough to remove the DAC over–range error. Optimum scaling varies with waveform content.
Basic Digital Operation Setting the Baseband Frequency Offset Setting the Baseband Frequency Offset The baseband frequency offset specifies a value to shift the baseband frequency up to ±20 MHz within the BBG 80 MHz signal bandwidth, depending on the signal generator’s baseband generator option. When the Baseband Frequency Offset is non–zero, the hardware rotator accumulates phase–shift of the baseband signal. This phase is automatically reset when the baseband frequency offset is returned to 0 Hz.
4 Optimizing Performance In the following sections, this chapter describes procedures that improve the performance of the Agilent PSG signal generator. • “Using the ALC” on page 129 • “Using External Leveling” on page 130 • “Creating and Applying User Flatness Correction” on page 133 • “Using the Option 521 Detector Calibration (Option 521)” on page 146 • “Adjusting Reference Oscillator Bandwidth (Option UNR/UNX/UNY)” on page 147 • “Optimizing Phase Noise and Harmonics Below 3.
Optimizing Performance Using External Leveling To Select an ALC Bandwidth Press Amplitude > ALC BW > 100 Hz, 1 kHz, 10 kHz, or 100 kHz. This overrides the signal generator’s automatic ALC bandwidth selection with your specific selection. For waveforms with varying amplitudes, high crest factors, or both, the recommended ALC loop bandwidth is 100 Hz.
Optimizing Performance Using External Leveling Figure 4-2 External Detector Leveling with a Directional Coupler Configure the Signal Generator 1. Press Preset. 2. Press Frequency > 10 > GHz. 3. Press Amplitude > 0 > dBm. 4. Press RF On/Off. 5. Press Leveling Mode > Ext Detector. This deactivates the internal ALC detector and switches the ALC input path to the front panel ALC INPUT connector. The EXT indicator is activated in the AMPLITUDE area of the display.
Optimizing Performance Using External Leveling Technologies diode detectors. Using this chart, you can determine the leveled power at the diode detector input by measuring the external detector output voltage. You must then add the coupling factor to determine the leveled output power. The range of power adjustment is approximately –20 to +25 dBm.
Optimizing Performance Creating and Applying User Flatness Correction External Leveling with Option 1E1 Signal Generators Signal generators with Option 1E1 contain a step attenuator prior to the RF output connector. During external leveling, the signal generator automatically holds the present attenuator setting (to avoid power transients that may occur during attenuator switching) as the RF amplitude is changed.
Optimizing Performance Creating and Applying User Flatness Correction generator’s RF output. Afterward, use the steps in Recalling and Applying a User Flatness Correction Array to recall a user flatness file from the memory catalog and apply it to the signal generator’s RF output.
Optimizing Performance Creating and Applying User Flatness Correction Creating a User Flatness Correction Array In this example, you create a user flatness correction array. The flatness correction array contains ten frequency correction pairs (amplitude correction values for specified frequencies), from 1 to 10 GHz in 1 GHz intervals.
Optimizing Performance Creating and Applying User Flatness Correction Figure 4-4 User Flatness Correction Equipment Setup Configure the Signal Generator 1. Press Preset. 2. Configure the signal generator to interface with the power meter. a. Press Amplitude > More (1 of 2) > User Flatness > More (1 of 2) > Power Meter > E4416A, E4417A, E4418B, or E4419B. b. Press Meter Address > enter the power meter’s GPIB address > Enter. c.
Optimizing Performance Creating and Applying User Flatness Correction 7. Press # of Points > 10 > Enter. Steps 4, 5, and 6 enter the desired flatness–corrected frequencies into the step array. 8. Press Return > Load Cal Array From Step Array > Confirm Load From Step Data. This populates the user flatness correction array with the frequency settings defined in the step array. 9. Press Amplitude > More (1 of 2) > Ampl Offset.
Optimizing Performance Creating and Applying User Flatness Correction 1. Press More (1 of 2) > User Flatness > Configure Cal Array. This opens the User Flatness table editor and places the cursor over the frequency value (1 GHz) for row 1. The RF output changes to the frequency value of the table row containing the cursor and 1.000 000 000 00 is displayed in the AMPLITUDE area of the display. 2. Observe and record the measured value from the power meter. 3. Subtract the measured value from 0 dBm. 4.
Optimizing Performance Creating and Applying User Flatness Correction 4. Ensure that the file FLATCAL1 is highlighted. 5. Press Load From Selected File > Confirm Load From File. This populates the user flatness correction array with the data contained in the file FLATCAL1. The user flatness correction array title displays User Flatness: FLATCAL1. 6. Press Return > Flatness Off On to On. This applies the user flatness correction data contained in FLATCAL1.
Optimizing Performance Creating and Applying User Flatness Correction Creating a User Flatness Correction Array with a mm–Wave Source Module CAUTION Option 521 signal generators can damage MM source modules. Consult the MM source module’s operating manual for input damage levels. In this example, a user flatness correction array is created to provide flatness–corrected power at the output of an Agilent 83554A millimeter–wave source module driven by an E8257D.
Optimizing Performance Creating and Applying User Flatness Correction NOTE For operating information on your particular power meter/sensor, refer to their operating guides. Connect the Equipment CAUTION To prevent damage to the signal generator, turn off the line power to the signal generator before connecting the source module interface cable to the rear panel SOURCE MODULE interface connector. Option 521 signal generators can damage MM source modules.
Optimizing Performance Creating and Applying User Flatness Correction Figure 4-5 142 User Flatness with mm–Wave Source Module for a Signal Generator without Options 1EA, 1EU, or 521 Chapter 4
Optimizing Performance Creating and Applying User Flatness Correction Figure 4-6 CAUTION NOTE User Flatness with mm–Wave Source Module for Signal Generators with Options 1EA, 1EU, or 521 Option 521 signal generators can damage MM source modules. Consult the MM source module’s operating manual for input damage levels.
Optimizing Performance Creating and Applying User Flatness Correction NOTE For specific frequency/amplitude ranges, see the mm–wave source module specifications. 2. Configure the signal generator to interface with the power meter. a. Press Amplitude > More (1 of 2) > User Flatness > More (1 of 2) > Power Meter > E4416A, E4417A, E4418B, or E4419B. b. Press Meter Address > enter the power meter’s GPIB address > Enter. c.
Optimizing Performance Creating and Applying User Flatness Correction and their calculated amplitude correction values. The user flatness correction array title displays User Flatness: (UNSTORED) indicating that the current user flatness correction array data has not been saved to the memory catalog.
Optimizing Performance Using the Option 521 Detector Calibration (Option 521) Recalling and Applying a User Flatness Correction Array Before performing the steps in this section, complete the section “Creating a User Flatness Correction Array with a mm–Wave Source Module” on page 140. 1. Press Preset. 2. Press Amplitude > More (1 of 2) > User Flatness > Configure Cal Array > More (1 of 2) > Preset List > Confirm Preset. 3. Press More (2 of 2) > Load/Store. 4. Ensure that the file FLATCAL2 is highlighted.
Optimizing Performance Adjusting Reference Oscillator Bandwidth (Option UNR/UNX/UNY) Adjusting Reference Oscillator Bandwidth (Option UNR/UNX/UNY) The reference oscillator bandwidth (sometimes referred to as loop bandwidth) in signal generators with Option UNR/UNX/UNY (improved close–in phase noise <1 kHz) is adjustable in fixed steps for either an internal or external 10 MHz frequency reference.
Optimizing Performance Optimizing Phase Noise and Harmonics Below 3.2 GHz (Option UNX/UNY) Optimizing Phase Noise Below 250 MHz (serial prefix > xx4928 and higher) This feature is available on instruments with Option UNX or Option UNY, and serial number prefix > xx4928 and higher. CAUTION Maximum available power below 3.2 GHz is lower when the Optimizing Phase Noise Below 250 MHz softkey is been pressed. Refer to the PSG’s Data Sheet.
Optimizing Performance Optimizing Phase Noise and Harmonics Below 3.2 GHz (Option UNX/UNY) Optimizing Harmonics Below 2 GHz CAUTION Maximum available power below 3.2 GHz, is lower when the Low Pass Filter Below 2 GHz softkey is been pressed. Refer to the PSG’s Data Sheet. The PSG’s harmonic performance can be improved below 3.2 GHz by using the Low Pass Filter Below 2 GHz softkey. Refer to the PSG’s Data Sheet.
Optimizing Performance Optimizing Phase Noise and Harmonics Below 3.
5 Analog Modulation In the following sections, this chapter describes the standard continuous waveform and optional analog modulation capability in the Agilent E8257D PSG Analog, E8663D, Analog, and E8267D PSG Vector signal generators.
Analog Modulation Configuring AM (Option UNT) Configuring AM (Option UNT) In this example, you will learn how to generate an amplitude–modulated RF carrier. To Set the Carrier Frequency 1. Press Preset. 2. Press Frequency > 1340 > kHz. To Set the RF Output Amplitude Press Amplitude > 0 > dBm. To Set the AM Depth and Rate 1. Press the AM hardkey. 2. Press AM Depth > 90 > %. 3. Press AM Rate > 10 > kHz.
Analog Modulation Configuring M (Option UNT) To Set the FM Deviation and Rate 1. Press the FM/M hardkey. 2. Press FM Dev > 75 > kHz. 3. Press FM Rate > 10 > kHz. The signal generator is now configured to output a 0 dBm, frequency–modulated carrier at 1 GHz with a 75 kHz deviation and a 10 kHz rate. The shape of the waveform is a sine wave. (Notice that sine is the default for the FM Waveform softkey. Press More (1 of 2) to see the softkey.) To Activate FM 1. Press FM Off On to On. 2. Press RF On/Off.
Analog Modulation Configuring Pulse Modulation (Option UNU/UNW) The signal generator is now configured to output a 0 dBm, phase–modulated carrier at 3 GHz with a 0.25 p radian deviation and 10 kHz rate. The shape of the waveform is a sine wave. (Notice that sine is the default for the M Waveform softkey. Press More (1 of 2) to see the softkey.) To Activate M 1. Press M Off On. 2. Press RF On/Off. The M and RF ON annunciators are now displayed.
Analog Modulation Configuring Pulse Modulation (Option UNU/UNW) Triggering Simultaneous Pulses from Two PSGs Using an Internal or an External Pulse Source Two PSG pulse generators can be triggered simultaneously using the PSG internal pulse generator or using an external pulse source. The pulse from PSG1 is triggered internally or by the external pulse generator and the pulse from PSG2 is triggered using the SYNC OUT signal from PSG1.
Analog Modulation Configuring the LF Output (Option UNT) Figure 5-1 4. Setup Diagram for Triggering Simultaneous Pulses Using Two PSGs If you are using: • "An external pulse source as the pulse trigger: Set the trigger mode to Internal Trigger for both PSGs by selecting the Pulse hardkey, and then selecting the Pulse Source and Internal Triggered on PSG 1 and PSG2. • "PSG1 as the internal pulse source: a.
Analog Modulation Configuring the LF Output (Option UNT) Dual–Sine dual–sine waves with individually adjustable frequencies and a percent–of– peak–amplitude setting for the second tone (available from function generator 1 only) Swept–Sine a swept–sine wave with adjustable start and stop frequencies, sweep rate, and sweep trigger settings (available from function generator 1 only) Triangle triangle wave with adjustable amplitude and frequency Ramp ramp with adjustable amplitude and frequency Square
Analog Modulation Configuring the LF Output (Option UNT) To Configure the LF Output with a Function Generator Source In this example, the function generator is the LF output source. Configuring the Function Generator as the LF Output Source 1. Press Preset. 2. Press the LF Out hardkey. 3. Press LF Out Source > Function Generator 1. Configuring the Waveform 1. Press LF Out Waveform > Swept–Sine. 2. Press LF Out Start Freq > 100 > Hz. 3. Press LF Out Stop Freq > 1 > kHz. 4. Press Return > Return.
6 Custom Arb Waveform Generator In the following sections, this chapter describes the custom arbitrary waveform generator mode, which is available only in E8267D PSG vector signal generators with Option 601 or 602: • “Overview” on page 159 • “Working with Predefined Setups (Modes)” on page 159 • “Working with Filters” on page 162 • “Working with Symbol Rates” on page 169 • “Working with Modulation Types” on page 171 • “Configuring Hardware” on page 178 See also: Chapter 3, “Basic Digital Operation,” on pa
Custom Arb Waveform Generator Working with User–Defined Setups (Modes)-Custom Arb Only 2. Press Mode > Custom > Arb Waveform Generator > Setup Select. 3.
Custom Arb Waveform Generator Working with User–Defined Setups (Modes)-Custom Arb Only 11. Press Digital Mod Define > Store Custom Dig Mod State > Store To File. If there is already a file name from the Catalog of DMOD Files occupying the active entry area, press: Edit Keys > Clear Text 12. Enter a file name (for example, NADCQPSK) using the alpha keys and the numeric keypad. 13. Press Enter. The user–defined single–carrier digital modulation state should now be stored in non–volatile memory.
Custom Arb Waveform Generator Working with Filters 12. Enter a file name (for example, EDGEM1) using the alpha keys and the numeric keypad, and press Enter. The user–defined multicarrier digital modulation state is now stored in non–volatile memory. NOTE The RF output amplitude, frequency, and operating state settings (such as RF On/Off) are not stored as part of a user–defined digital modulation state file. For more information, refer to “Using Data Storage Functions” on page 61.
Custom Arb Waveform Generator Working with Filters middle, and total attenuation at high frequencies. The width of the middle frequencies is defined by the roll off factor or Filter Alpha (0 < Filter Alpha < 1). • Gaussian is a Gaussian pre–modulation FIR filter. • User FIR enables you to select from a Catalog of FIR filters; use this selection if the other predefined FIR filters do not meet your needs. For more information, see Define User FIR, below.
Custom Arb Waveform Generator Working with Filters Optimizing a Nyquist or Root Nyquist FIR Filter for EVM or ACP (Custom Realtime I/Q Baseband only) 1. Preset the instrument: Press Preset. 2. Press Mode > Custom > Real Time I/Q Baseband > Filter > Optimize FIR For EVM or ACP. The FIR filter is now optimized for minimum error vector magnitude (EVM) or for minimum adjacent channel power (ACP).
Custom Arb Waveform Generator Working with Filters 7. Press Display Impulse Response. A graph displays the impulse response of the current FIR coefficients. 8. Press Return. 9. Highlight coefficient 15. 10. Press 0 > Enter. 11. Press Display Impulse Response. The graphic display can provide a useful troubleshooting tool (in this case, it indicates that a coefficient value is set incorrectly, resulting in an improper Gaussian response). 12. Press Return. 13. Highlight coefficient 15. 14.
Custom Arb Waveform Generator Working with Filters To Create a User–Defined FIR Filter with the FIR Values Editor In this procedure, you use the FIR Values editor to create and store an 8–symbol, windowed, sinc function filter with an oversample ratio of 4. The Oversample Ratio (OSR) is the number of filter coefficients per symbol. You can define from 1 to 32 FIR coefficients, where the maximum combination of symbols and oversample ratio is 1024 coefficients.
Custom Arb Waveform Generator Working with Filters Coefficient Value Coefficient Value Coefficient Value 0 0.000076 6 0.043940 12 0.123414 1 0.001747 7 0.025852 13 0.442748 2 0.005144 8 0.035667 14 0.767329 3 0.004424 9 0.116753 15 0.972149 4 0.007745 10 0.157348 5 0.029610 11 0.088484 7. Press Mirror Table. In a windowed sinc function filter, the second half of the coefficients are identical to the first half, but in reverse order.
Custom Arb Waveform Generator Working with Filters 9. Press More (1 of 2) > Display FFT (fast Fourier transform). A graph displays the fast Fourier transform of the current set of FIR coefficients. The signal generator has the capability of graphically displaying the filter in both time and frequency dimensions. 10. Press Return > Display Impulse Response. A graph shows the impulse response of the current set of FIR coefficients. 11. Press Return > Load/Store > Store To File.
Custom Arb Waveform Generator Working with Symbol Rates Working with Symbol Rates The Symbol Rate menu enables you to set the rate at which I/Q symbols are fed to the I/Q modulator. The default transmission symbol rate can also be restored in this menu. • Symbol Rate (displayed as Sym Rate) is the number of symbols per second that are transmitted using the modulation (displayed as Mod Type) along with the filter and filter alpha (displayed as Filter).
Custom Arb Waveform Generator Working with Symbol Rates To Restore the Default Symbol Rate (Custom Real Time I/Q Only) • Press Mode > Custom > Real Time I/Q Baseband > Symbol Rate > Restore Default Symbol Rate. This replaces the current symbol rate with the default symbol rate for the selected modulation format.
Custom Arb Waveform Generator Working with Modulation Types Modulation Type QAM Quadratu re Amplitud e Modulatio n Bits Per Symbol Bit Rate = Symbols/s x Number of Bits/Symbol Internal Symbol Rate (Minimum Maximum) Custom Real Time Only External Symbol Rate (Minimum Maximum) 4QAM 2 90 bps 100 Mbps 45 sps 50 Msps 45 sps 25 Msps 16QAM 4 180 bps 200 Mbps 45 sps 50 Msps 45 sps 12.
Custom Arb Waveform Generator Working with Modulation Types To Use a User–Defined Modulation Type (Real Time I/Q Only) Creating a 128QAM I/Q Modulation Type User File with the I/Q Values Editor In I/Q modulation schemes, symbols appear in default positions in the I/Q plane. Using the I/Q Values editor, you can define your own symbol map by changing the position of one or more symbols. Use the following procedure to create and store a 128–symbol QAM modulation.
Custom Arb Waveform Generator Working with Modulation Types 5. Press the Delete Row softkey 16 times. Repeat this pattern of steps using the following table: Goto Row... Press the Delete Row softkey...
Custom Arb Waveform Generator Working with Modulation Types 2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User I/Q > More (1 of 2) > Delete All Rows > Confirm Delete All Rows. This loads a default 4QAM I/Q modulation and clears the I/Q Values editor. 3. Enter the I and Q values listed in the following table: Symbol Data I Value Q Value 0 1 2 3 a. Press 0.
Custom Arb Waveform Generator Working with Modulation Types Modifying a Predefined I/Q Modulation Type (I/Q Symbols) & Simulating Magnitude Errors & Phase Errors Use the following procedure to manipulate symbol locations which simulate magnitude and phase errors. In this example, you edit a 4QAM constellation to move one symbol closer to the origin. 1. Press Preset. 2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User I/Q > More (1 of 2) > Load Default I/Q Map > QAM > 4QAM.
Custom Arb Waveform Generator Working with Modulation Types 6. Press –1.8 > kHz. Each time you enter a value, the Data column increments to the next binary number, up to a total of 16 data values (from 0000 to 1111). An unstored file of frequency deviation values is created for the custom 4–level FSK file. 7. Press Load/Store > Store To File. If there is already a file name from the Catalog of FSK Files occupying the active entry area, press the following keys: Edit Keys > Clear Text 8.
Custom Arb Waveform Generator Working with Modulation Types Differential Wideband IQ (Option 016) The signal generator with Option 016 can use an external I/Q modulation source such as a two channel arbitrary waveform generator to generate up to 2 GHz modulation bandwidth at RF. To enable the wideband I/Q inputs: 1. Press the front panel I/Q hardkey. 2. Press I/Q Off. 3. Press I/Q Path Wide (Ext Rear Inputs). 4. Press I/Q On.
Custom Arb Waveform Generator Configuring Hardware the internal ARB as a baseband source and enable the wideband inputs. 1. Set up the internal baseband generator with the desired signal. 2. Press the Mux hardkey. 3. Press I/Q Out. 4. Press BBG1 5. Press the front panel I/Q hardkey. 6. Press I/Q Off. 7. Press I/Q Path Wide (Ext Rear Inputs). 8. Press I/Q On.
Custom Arb Waveform Generator Configuring Hardware The Custom Arb Waveform Generator has been configured to play a single multicarrier waveform 100 milliseconds after it detects a change in TTL state from low to high at the PATT TRIG IN rear panel connector. 10. Set the function generator waveform to a 0.1 Hz square wave at an output level of 0 to 5V. 11. On the signal generator, press Mode > Custom > Arb Waveform Generator > Digital Modulation Off On until On is highlighted.
Custom Arb Waveform Generator Configuring Hardware 180 Chapter 6
7 Custom Real Time I/Q Baseband In the following sections, this chapter describes the custom real–time I/Q baseband mode, which is available only in E8267D PSG vector signal generators with Option 601 or 602: • “Overview” on page 181 • “Working with Predefined Setups (Modes)” on page 181 • “Working with Data Patterns” on page 182 • “Working with Burst Shapes” on page 187 • “Configuring Hardware” on page 191 • “Working with Phase Polarity” on page 192 • “Working with Differential Data Encoding” on page 192
Custom Real Time I/Q Baseband Working with Data Patterns Deselecting a Predefined Real Time Modulation Setup To deselect any predefined mode that has been previously selected, and return to the top–level custom modulation menu: 1. Press Preset. 2. Press Mode > Custom > Real Time I/Q Baseband. 3. Press More (1 of 3) > More (2 of 3) > Predefined Mode > None. 4. Press More (3 of 3).
Custom Real Time I/Q Baseband Working with Data Patterns Using a Predefined Data Pattern Selecting a Predefined PN Sequence Data Pattern 1. Press Preset. 2. Press Mode > Custom > Real Time I/Q Baseband > Data > PN Sequence. 3. Press one of the following: PN9, PN11, PN15, PN20, PN23. Selecting a Predefined Fixed 4–bit Data Pattern 1. Press Preset. 2. Press Mode > Custom > Real Time I/Q Baseband > Data > FIX4. 3. Press 1010 > Enter > Return.
Custom Real Time I/Q Baseband Working with Data Patterns Offset (in Hex) NOTE Bit Data Cursor Position indicator (in Hex) Hexadecimal Data File Name indicator When you create a new file, the default name is UNTITLED, or UNTITLED1, and so forth. This prevents overwriting previous files. 3. Using the numeric keypad (not the softkeys), enter the 32 bit values shown. Bit data is entered into the Bit File Editor in 1–bit format.
Custom Real Time I/Q Baseband Working with Data Patterns Enter These Bit Values Hexadecimal Data Cursor Position 4. Press More (1 of 2) > Rename > Editing Keys > Clear Text. 5. Enter a file name (for example, USER1) using the alpha keys and the numeric keypad. 6. Press Enter. The user file should be renamed and stored to the Memory Catalog with the name USER1.
Custom Real Time I/Q Baseband Working with Data Patterns Navigating the Bit Values of an Existing Data Pattern User File 1. Press Goto > 4 > C > Enter. This moves the cursor to bit position 4C, of the table, as shown in the following figure. Cursor moves to new position Position indicator changes Inverting the Bit Values of an Existing Data Pattern User File 1. On the keypad, press 1011. This inverts the bit values that are positioned 4C through 4F.
Custom Real Time I/Q Baseband Working with Burst Shapes To Apply Bit Errors to an Existing Data Pattern User File This example demonstrates how to apply bit errors to an existing data pattern user file. If you have not created and stored a data pattern user file, first complete the steps in the previous section, “Creating a Data Pattern User File with the Bit File Editor” on page 183. 1. Press Apply Bit Errors. 2. Press Bit Errors > 5 > Enter. 3. Press Apply Bit Errors.
Custom Real Time I/Q Baseband Working with Burst Shapes User–Define d Values User–Define d Values Power 1 0 Rise Delay Rise Time Fall Delay Fall Time Time Burst shape maximum rise and fall time values are affected by the following factors: • the symbol rate • the modulation type When the rise and fall delays equal 0, the burst shape attempts to synchronize the maximum burst shape power to the beginning of the first valid symbol and the ending of the last valid symbol.
Custom Real Time I/Q Baseband Working with Burst Shapes You can also design burst shape files externally and download the data to the signal generator. For more information, see the Agilent Signal Generators Programming Guide. To Create and Store User–Defined Burst Shape Curves Using this procedure, you learn how to enter rise shape sample values and mirror them as fall shape values to create a symmetrical burst curve. 1. Press Preset. 2. Press Mode > Custom > Real Time I/Q Baseband > Burst Shape. 3.
Custom Real Time I/Q Baseband Working with Burst Shapes Figure 7-1 5. Press More (1 of 2) > Display Burst Shape. This displays a graphical representation of the waveform’s rise and fall characteristics. Figure 7-2 NOTE To return the burst shape to the default conditions, press Return > Return > Confirm Exit From Table Without Saving > Restore Default Burst Shape. 6. Press Return > Load/Store > Store To File.
Custom Real Time I/Q Baseband Configuring Hardware 8. Press Enter. The contents of the current Rise Shape and Fall Shape editors are stored to the Catalog of SHAPE Files. This burst shape can now be used to customize a modulation or as a basis for a new burst shape design. To Select and Recall a User–Defined Burst Shape Curve from the Memory Catalog Once a user–defined burst shape file is stored in the Memory Catalog, it can be recalled for use with real–time I/Q baseband generated digital modulation.
Custom Real Time I/Q Baseband Working with Phase Polarity SYMBOL SYNC input connector. To Set the BBG DATA CLOCK to External or Internal 1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Configure Hardware. Configure Hardware allows you to access a menu from which you can set the BBG DATA CLOCK to receive input from External or Internal. 2. Press BBG Data Clock Ext Int to select either external or internal.
Custom Real Time I/Q Baseband Working with Differential Data Encoding This section provides information about the following: • Understanding Differential Encoding • “Using Differential Encoding” on page 197 Understanding Differential Encoding Differential encoding is a digital–encoding technique whereby a binary value is denoted by a signal change rather than a particular signal state.
Custom Real Time I/Q Baseband Working with Differential Data Encoding The following illustration shows a 4QAM modulation I/Q State Map.
Custom Real Time I/Q Baseband Working with Differential Data Encoding For a bit–by–bit illustration of the encoding process, see the following illustration: 0 1 0 1 0 0 1 1 0 0 1 0 1 raw (unencoded) data change = no change = 1 1 1 1 0 1 0 1 0 1 1 1 1 differentially encoded data How Differential Encoding Works Differential encoding employs offsets in the symbol table to encode user–defined modulation schemes.
Custom Real Time I/Q Baseband Working with Differential Data Encoding NOTE The following I/Q State Map illustrations show all possible state transitions using a particular symbol table offset value. The actual state–to–state transition depends on the state in which the modulation starts.
Custom Real Time I/Q Baseband Working with Differential Data Encoding 1st 1st Symbol 3rd Symbol { { { 2nd 5th Symbol 2nd Symbol 5th 3rd { { Data = 0011100001 4th Symbol 4th Data Value 00 01 10 11 Symbol Table Offset +1 –1 +2 +0 When applied to the user–defined default 4QAM I/Q map, starting from the 1st symbol (data 00), the differential encoding transitions for the data stream (in 2–bit symbols) 0011100001 appear in the previous illustration.
Custom Real Time I/Q Baseband Working with Differential Data Encoding Configuring User–Defined I/Q Modulation 1. Press Preset. 2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User I/Q > More (1 of 2) > Load Default I/Q Map > QAM > 4QAM. This loads a default 4QAM I/Q modulation and displays it in the I/Q Values editor. The default 4QAM I/Q modulation contains data that represent 4 symbols (00, 01, 10, and 11) mapped into the I/Q plane using 2 distinct values (1.000000 and 1.
Custom Real Time I/Q Baseband Working with Differential Data Encoding Data Symbol Table Offset Values Entry Area Editing the Differential State Map 1. Press 1 > Enter. This encodes the first symbol by adding a symbol table offset of 1. The symbol rotates forward through the state map by 1 value when a data value of 0 is modulated. 2. Press +/– > 1 > Enter. This encodes the second symbol by adding a symbol table offset of –1.
Custom Real Time I/Q Baseband Working with Differential Data Encoding 5. Press Return > Differential Encoding Off On. This applies the custom differential encoding to a user–defined modulation. NOTE Notice that (UNSTORED) appears next to Differential State Map on the signal generator’s display. Differential state maps are associated with the user–defined modulation for which they were created. To save a custom differential state map, you must store the user–defined modulation for which it was designed.
8 GPS Modulation (Option 409) Option 409 includes real time multiple-satellite and single-satellite global positioning system (GPS) signal generation capabilities. This feature is available only in E8267D PSG Vector Signal Generators with Option 602.
GPS Modulation (Option 409) Real Time MSGPS Real Time MSGPS In Real Time MSGPS mode, selectable scenario files define simulated multiple-satellite conditions. The E8267D generates a signal (C/A code only) simulating multiple satellite transmissions from the information in the selected scenario file.
GPS Modulation (Option 409) Real Time MSGPS Signal Generation Block Diagram Figure 8-1 shows how the signal is generated within the PSG for a four satellite MSGPS simulation. The PSG produces a simulated signal for each satellite and then sums them together to produce the MSGPS signal. Use the Number of Satellites softkey to specify the number of satellites in the MSGPS simulation.
GPS Modulation (Option 409) Real Time MSGPS Scenario Files When you install option 409, a GPS directory is created in the PSG non-volatile memory and two MSGPS scenario files are loaded into the GPS directory. Additional scenario files are available for Option 409. (Go to http://www.agilent.com/find/gps.
GPS Modulation (Option 409) Real Time MSGPS 9. Type exit to end the command prompt session. Downloading Scenario Files Using SCPI Commands (GPIB) The following procedure describes how to download scenario files to a PSG using a SCPI command on a PC connected to your PSG through a GPIB interface: 1. Open your web browser and type in the IP address of your PSG. The PSG’s Welcome webpage is displayed. 2. Click Signal Generator Web Control.
GPS Modulation (Option 409) Real Time MSGPS how to obtain the CNO value from the GPGSV message. The following example is a set of three GPGSV messages. The receiver produces a maximum of three GPGSV messages every second. The fields are comma-separated; two adjacent commas signify a field for which a value is not assigned.
GPS Modulation (Option 409) Real Time MSGPS Table 8-1 describes each field for the first of the three GPGSV messages in the example: $GPGSV,3,1,12,21,71,000,,27,68,000,34,08,62,000,33,29,52,000,,*71 Table 8-1 GPGSV Fields GPGSV Field Description $GPGSV, 3, Number of GPGSV messages in this set 1, Number of this GPGSV in the set (1 of 3) 12, Total number of satellites in view 21,71,000,, Satellite 21, elevation 71, azimuth 0, CNO unknown 27,68,000,34 Satellite 27, elevation 68, azimuth 0, CNO 34
GPS Modulation (Option 409) Real Time MSGPS Generating a Real Time MSGPS Signal This procedure uses the internal reference clock with the factory preset settings (the C/A chip rate is 1.023 Mcps with a clock reference of 10.23 Mcps). Set the carrier frequency and amplitude 1. Press the Preset hardkey. 2. Press the Frequency hardkey. Using the numeric keypad, set the signal generator RF output carrier frequency to 1.57542 GHz. 3. Press the Amplitude hardkey.
GPS Modulation (Option 409) Real Time MSGPS Figure 8-2 Real Time MSGPS Scenario Configuring the External Reference Clock 1. Connect the external reference clock source to the rear panel connector BASEBAND GEN REF IN. 2. Set the chip rate of the external clock to the desired value. 3. Press Mode > More (1 of 2) > GPS > Real Time MSGPS > More (1 of 2) > GPS Ref Clk Ext Int to Ext. 4. Press GPS Ref (f0). 5. Use the numeric keypad to set the GPS reference clock to the same chip rate as the external clock.
GPS Modulation (Option 409) Real Time GPS Real Time GPS This real-time personality simulates GPS satellite transmissions for single channel receiver testing. Basic GPS signal building capabilities include: • P code generation at 10.23 Mcps with the standard GPS 10.23 Mcps reference1 • C/A code generation at 1.023 Mcps with the standard GPS 10.
GPS Modulation (Option 409) Real Time GPS Real Time GPS Introduction Signal Generation Block Diagram Figure 8-3 shows how the GPS signal is generated within the PSG. Notice that the C/A code modulates the L-band signal using the I axis of the I/Q modulator, and the P code modulates the L-band signal using the Q axis. Select the data provided by the data generator using the Data softkey or by choosing the TLM data mode.
GPS Modulation (Option 409) Real Time GPS Data Modes and Subframe Structures You can select one of the three following data modes for use with the C/A or C/A+P ranging code: • Raw - The Raw data mode enables the continuous transmission of 300 bits of data per subframe without incorporating parity bits. Use this mode for BER and low-level demodulation testing.
GPS Modulation (Option 409) Real Time GPS The TLM word is 30-bits long, with an 8-bit preamble, 16 reserve bits (bits 9 to 24, all set to zero), and 6 parity bits (bits 25 to 30). The HOW word is 30-bits long, with the first 17 bits used for an incrementing time-of-week (TOW), bits 23 and 24 used for parity computation, and bits 25 to 30 used for parity bits. During a GPS signal transmission, a pulse signal is generated every 6 seconds at the EVENT 1 rear panel connector.
GPS Modulation (Option 409) Real Time GPS Rear Panel Signal Synchronization Figure 8-5 illustrates the timing relationships of the GPS signals available at the signal generator rear panel. The AUX I/O connector outputs the SYMBOL SYNC OUT, DATA CLOCK OUT, and DATA OUT signals (refer to, “5. AUXILIARY I/O” on page 25 for more information). EVENT 1 and EVENT 2 are BNC connectors. If the signal generator is configured with Option 1EM, EVENT 1 and EVENT 2 connectors are changed from BNC to SMB connectors.
GPS Modulation (Option 409) Real Time GPS User Files You can create data files internally in the PSG or create them externally and download them to the PSG. In either case, the size of user data files is limited by the amount of available PSG memory. If you develop data files externally, you can define signal structures that are not available internally in the PSG.
GPS Modulation (Option 409) Real Time GPS Setting Up the Real Time GPS Signal If the signal generator is in the factory-defined preset mode, (Utility > Power On/Preset > Preset Normal User to Normal) a basic GPS signal is automatically set up when you press the Preset key. Perform step 2 and steps 6 through 8 to generate a signal at the RF OUTPUT connector. To set up a signal using additional features of the GPS personality, complete this procedure starting with step 1. 1. Press Preset. 2.
GPS Modulation (Option 409) Real Time GPS Figure 8-6 Real Time GPS Setup with Internal Clock Configuring the External Reference Clock 1. Access the real-time GPS personality (Mode > More(1 of 2) > GPS > Real Time GPS). 2. Press More (1 of 2) > GPS Ref Clk Ext Int to Ext. 3. Press GPS Ref (f0) > 11.03 > kcps. 4. Connect the external reference clock source to the DATA CLOCK INPUT connector. The maximum clock rate for this input connector is 50 MHz with a voltage range of 0.5 to 5.5 V. 5.
GPS Modulation (Option 409) Real Time GPS Figure 8-7 Real Time GPS Setup with External Clock This procedure used an external source as the reference clock signal. The reference frequency was changed from the GPS standard of 10.23 Mcps to 11.03 kcps. This change in the reference signal frequency automatically changed the P and C/A code chip rates. Since the P code chip rate matches the reference frequency, its chip rate is now 11.
GPS Modulation (Option 409) Real Time GPS Testing Receiver Sensitivity Refer to Figure 8-8. 1. Connect the cables between the receiver and the PSG as shown in Figure 8-8. Figure 8-8 Setup for a Receiver Sensitivity Test 2. Set the GPS data mode to TLM. 3. Set the power level on the PSG. 4. Set the L-band frequency on the PSG. 5. Set up the UE (user equipment) to receive the signal from the PSG. 6. Turn on the GPS personality and the RF output on the PSG.
GPS Modulation (Option 409) Real Time GPS 220 Chapter 8
9 Multitone Waveform Generator In the following sections, this chapter describes the multitone mode, which is available only in E8267D PSG Vector Signal Generators with Option 601 or 602: • “Overview” on page 221 • “Creating, Viewing, and Optimizing Multitone Waveforms” on page 222 See also: Chapter 3, “Basic Digital Operation,” on page 79 Overview The multitone mode builds a waveform that has up to 64 CW signals, or tones.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms Creating, Viewing, and Optimizing Multitone Waveforms This section describes how to set up, generate, and optimize a multitone waveform while viewing it with a spectrum analyzer. Although you can view a generated multitone signal using any spectrum analyzer that has sufficient frequency range, an Agilent Technologies PSA high–performance spectrum analyzer was used for this demonstration.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms The waveform has nine tones spaced 1 MHz apart with random initial phase values. The center tone is placed at the carrier frequency, while the other eight tones are spaced in 1 MHz increments from the center tone. If you create an even number of tones, the carrier frequency will be centered between the two middle tones.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms Figure 9-3 Multitone Channels Intermodulation Distortion To Edit the Multitone Setup Table This procedure builds upon the previous procedure. 1. Press Initialize Table > Number of Tones > 10 > Enter. 2. Press Done. 3. Highlight the value (On) in the State column for the tone in row 2. 4. Press Toggle State. 5. Highlight the value (0 dB) in the Power column for the tone in row 4. 6. Press Edit Item > –10 > dB. 7.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms 9. Press Apply Multitone. NOTE Whenever a change is made to a setting while the multitone generator is operating (Multitone Off On set to On), you must apply the change by pressing the Apply Multitone softkey before the updated waveform will be generated. When you apply a change, the baseband generator creates a multitone waveform using the new settings and replaces the existing waveform in ARB memory.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms Figure 9-5 Tone 1 Tone 10 Carrier Feedthrough Intermodulation Distortion Carrier Feedthrough Distortion To Minimize Carrier Feedthrough This procedure describes how to minimize carrier feedthrough and measure the difference in power between the tones and their intermodulation distortion products. Carrier feedthrough can only be observed with even–numbered multitone waveforms.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms 7. Turn on waveform averaging. 8. Create a marker and place it on the peak of one of the end tones. 9. Create a delta marker and place it on the peak of the adjacent intermodulation product, which should be spaced 10 MHz from the marked tone. 10. Measure the power difference between the tone and its distortion product. You should now see a display that is similar to the one shown in Figure 9- 6.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms 4. Press Done. 5. Press Apply Multitone. 6. Press More (1 of 2) > ARB Setup > Waveform Utilities > Waveform Statistics > Plot CCDF. You should now see a display that is similar to the one shown in Figure 9- 7. The CCDF plot displays the peak to average characteristics of the waveform with all phases set to zero. Figure 9-7 CCDF Plot with Fixed Phase Set Peak Power 7. Press Mode Setup > Initialize Table. 8.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms Figure 9-8 CCDF Plot with Random Phase Set Peak Power Chapter 9 229
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms 230 Chapter 9
10 Two–Tone Waveform Generator In the following sections, this chapter describes the two–tone mode, which is available only in E8267D PSG vector signal generators with Option 601 or 602: • “Overview” on page 231 • “Creating, Viewing, and Modifying Two–Tone Waveforms” on page 231 See also: “Arbitrary (ARB) Waveform File Headers” on page 80 Overview The two–tone mode builds a waveform that has two equal–powered CW signals, or tones.
Two–Tone Waveform Generator Creating, Viewing, and Modifying Two–Tone Waveforms Figure 10-1 Spectrum Analyzer Setup To Create a Two–Tone Waveform This procedure describes how to create and a basic, center–aligned, two–tone waveform. 1. Preset the signal generator. 2. Set the signal generator RF output frequency to 20 GHz. 3. Set the signal generator RF output amplitude to 0 dBm. 4. Press Mode > Two Tone > Freq Separation > 10 > MHz. 5. Press Two Tone Off On to On. 6. Turn on the RF output.
Two–Tone Waveform Generator Creating, Viewing, and Modifying Two–Tone Waveforms Figure 10-2 To View a Two–Tone Waveform This procedure describes how to configure the spectrum analyzer to view a two–tone waveform and its IMD products. Actual key presses will vary, depending on the model of spectrum analyzer you are using. 1. Preset the spectrum analyzer. 2. Set the carrier frequency to 20 GHz. 3. Set the frequency span to 60 MHz. 4. Set the amplitude for a 10 dB scale with a 4 dBm reference. 5.
Two–Tone Waveform Generator Creating, Viewing, and Modifying Two–Tone Waveforms Figure 10-3 Two–Tone Channels Carrier Feedthrough Intermodulation Distortion Carrier Feedthrough Distortion To Minimize Carrier Feedthrough This procedure describes how to minimize carrier feedthrough and measure the difference in power between the tones and their intermodulation distortion products. Carrier feedthrough only occurs with center–aligned two–tone waveforms. This procedure builds upon the previous procedure.
Two–Tone Waveform Generator Creating, Viewing, and Modifying Two–Tone Waveforms 6. On the spectrum analyzer, return the resolution bandwidth to its previous setting. 7. Turn on waveform averaging. 8. Create a marker and place it on the peak of one of the two tones. 9. Create a delta marker and place it on the peak of the adjacent intermodulation product, which should be spaced 10 MHz from the marked tone. 10. Measure the power difference between the tone and its distortion product.
Two–Tone Waveform Generator Creating, Viewing, and Modifying Two–Tone Waveforms 1. On the signal generator, press Mode Setup > Alignment Left Cent Right to Left. 2. Press Apply Settings to regenerate the waveform. NOTE Whenever a change is made to a setting while the two–tone generator is operating (Two Tone Off On set to On), you must apply the change by pressing the Apply Settings softkey before the updated waveform will be generated.
11 AWGN Waveform Generator In the following sections, this chapter contains examples for using the AWGN waveform generator, which is available only in E8267D vector PSGs with Options 601 or 602 and Option 403: • “Arb Waveform Generator AWGN” on page 237 • “Real Time I/Q Baseband AWGN” on page 238 For adding real–time AWGN to waveforms using the Dual ARB player, see “Adding Real–Time Noise to a Dual ARB Waveform (E8267D with Option 403)” on page 95 Configuring the AWGN Generator The AWGN (additive white G
AWGN Waveform Generator Configuring the AWGN Generator Generating the Waveform Press AWGN Off On until On is highlighted. This generates an AWGN waveform with the parameters defined in the previous procedure. During waveform generation, the AWGN and I/Q annunciators activate and the AWGN waveform is stored in volatile ARB memory. The waveform is now modulating the RF carrier. Real Time I/Q Baseband AWGN 1. Press Preset. 2. Press Mode > More (1 of 2) > AWGN > Real Time I/Q Baseband AWGN 3.
12 Peripheral Devices This chapter provides information on peripheral devices used with PSG signal generators.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-1 Data Setup Menu for a Parallel Port Configuration Least significant bit Most significant bit Clock and sample rates See the PSG User’s Guide for information The N5102A module clock rate is set using the Clock Rate softkey and has a range of 1 kHz to 400 MHz. The sample rate is automatically calculated and has a range of 1 kHz to 100 MHz. These ranges can be smaller depending on logic type, data parameters, and clock configuration.
Peripheral Devices N5102A Digital Signal Interface Module Table 12-2 Warranted Parallel Input Level Clock Rates and Maximum Clock Rates Logic Type Warranted Level Clock Rates Maximum Clock Rates (typical) LVTTL and CMOS 100 MHz 100 MHz LVDS 100 MHz 400 MHz The levels will degrade above the warranted level clock rates, but they may still be usable.
Peripheral Devices N5102A Digital Signal Interface Module Parallel and Parallel Interleaved Port Configuration Clock Rates Parallel and parallel interleaved port configurations have other limiting factors for the clock and sample rates: • logic type • Clocks per sample selection • IQ or IF digital signal type Clocks per sample (clocks/sample) is the ratio of the clock to sample rate. For an IQ signal type, the sample rate is reduced by the clocks per sample value when the value is greater than one.
Peripheral Devices N5102A Digital Signal Interface Module Clock Source The clock signal for the N5102A module is provided in one of three ways through the following selections: • Internal: generated internally in the interface module (requires an external reference) • Externalgenerated externally through the Ext Clock In connector • Devicegenerated externally through the Device Interface connector The clock source is selected using the N5102A module UI on the signal generator, as shown in Figure 12-
Peripheral Devices N5102A Digital Signal Interface Module clock inside the signal generator must have the same base frequency reference as the clock used by the device under test. PSG Frequency Reference Connections When a frequency reference is connected to the PSG, it is applied to one of two rear- panel connectors: • 10 MHz IN • BASEBAND GEN REF IN The BASEBAND GEN REF IN connector will accept a frequency reference in the range of 1 to 100 MHz.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-3 Frequency Reference Setup Diagrams for the N5102A Module Clock Signal Internally Generated Clock Device (DUT) Supplied Clock NOTE: Use only one of the two signal generator frequency reference inputs.
Peripheral Devices N5102A Digital Signal Interface Module Externally Supplied Clock NOTE: Use only one of the two signal generator frequency reference inputs. Clock Timing for Parallel Data Some components require multiple clocks during a single sample period. (A sample period consists of an I and Q sample). For parallel data transmissions, you can select one, two, or four clocks per sample.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-4 Clock Sample Timing for Parallel Port Configuration 1 Clock Per Sample 1 Sample Period 1 Clock Clock and sample rates are the same Clock I sample 4 bits per word Q sample 4 bits per word Chapter 12 247
Peripheral Devices N5102A Digital Signal Interface Module 2 Clocks Per Sample Sample rate decreases by a factor of two 1 Sample Period 2 Clocks Clock I sample 4 bits per word Q sample 4 bits per word 4 Clocks Per Sample Sample rate decreases by a factor of four 1 Sample Period 4 Clocks Clock I sample 4 bits per word Q sample 4 bits per word 248 Chapter 12
Peripheral Devices N5102A Digital Signal Interface Module Clock Timing for Parallel Interleaved Data The N5102A module provides the capability to interleave the digital I and Q samples. There are two choices for interleaving: • IQ, where the I sample is transmitted first • QI, where the Q sample is transmitted first When parallel interleaved is selected, all samples are transmitted on the I data lines.
Peripheral Devices N5102A Digital Signal Interface Module 2 Clocks Per Sample The I sample is transmitted for one clock period and the Q sample is transmitted during the second clock period; the sample rate decreases by a factor of two.
Peripheral Devices N5102A Digital Signal Interface Module Clock Timing for Serial Data Figure 12- 6 shows the clock timing for a serial port configuration. Notice that the serial transmission includes frame pulses that mark the beginning of each sample while the clock delineates the beginning of each bit. For serial transmission, the clock and the bit rates are the same, but the sample rate varies depending on the number of bits per word that are entered using the Word Size softkey.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-7 Clock Phase and Skew Adjustments 90 degree phase adjustment Clock skew adjustment Phase and skew adjusted clock Phase adjusted clock Clock Data Connecting the Clock Source and the Device Under Test As shown in Figure 12- 3 on page 245, there are numerous ways to provide a common frequency reference to the system components (PSG, N5102A module, and the device under test).
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-8 Example Setup using the PSG 10 MHz Frequency Reference Signal generator 10 MHz Out Common Freq Ref cable Freq Ref connector Device under test Break-out board Device interface connection User furnished ribbon cable(s) connect between the device and break-out board. The clock to the device is in the ribbon cable. 1.
Peripheral Devices N5102A Digital Signal Interface Module Data Types The following block diagram indicates where in the PSG signal generation process the data is injected for input mode or tapped for output mode. Output Mode Pre-FIR Samples Samples PSG LO FIR Data Generator I,Q DACs Filtering Pre-FIR Samples RF I/Q Modulator Samples Input Mode Output Mode When using an ARB format, the data type is always Samples and no filtering is applied to the data samples.
Peripheral Devices N5102A Digital Signal Interface Module Table 12-7 Maximum Sample Rate for Selected Filter Filter Maximum Rate Gaussian Nyquist Root Nyquist Rectangle Edge UN3/4 GSM Gaussian IS- 95 IS 95 w/EQ 50 MHz IS- 95 Mod IS- 95 Mod w/EQ 25 MHz APCO 25 C4FM 12.5 MHz The Filter softkey accesses a menu that enables you set the desired filtering parameters.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-9 First-Level Softkey Menu Line is grayed out until the N5102A module interface is turned on Choosing the Logic Type and Port Configuration Figure 12-10 Logic and Port Configuration Softkey Menus 1. Refer to Figure 12- 10. Press the Logic Type softkey. From this menu, choose a logic type.
Peripheral Devices N5102A Digital Signal Interface Module CAUTION Changing the logic type can increase or decrease the signal voltage level going to the device under test. To avoid damaging the device and/or the N5102A module, ensure that both are capable of handling the voltage change. 2. Select the logic type required for the device being tested. A caution message is displayed whenever a change is made to the logic types, and a softkey selection appears requesting confirmation. 3.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-11 Data Setup Menu Location Accesses the data setup menu This softkey menu accesses the various parameters that govern the data received by the device under test. The status area of the display shows the number of data lines used for both I and Q along with the clock position relative to the data. When the port configuration is parallel or parallel interleaved, the number of data lines indicated is equivalent to the word (sample) size.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-12 Data Setup Softkey Menu with Parallel Port Configuration Inactive for ARB formats Inactive for word size = 16 bits Inactive for a serial port configuration Frame polarity is active for a serial port configuration 2. If a real- time modulation format is being used, press the Data Type softkey. (This softkey is inactive when an ARB modulation format is turned on.
Peripheral Devices N5102A Digital Signal Interface Module 6. Press the More (1 of 2) softkey. From this softkey menu, select the bit order, swap I and Q, select the polarity of the transmitted data, and access menus that provide data negation, scaling, gain, offset, and IQ rotation adjustments. 7. Press the Data Negation softkey. Negation differs from changing the I and Q polarity.
Peripheral Devices N5102A Digital Signal Interface Module From this softkey menu, set all of the clock parameters that synchronize the clocks between the N5102A module and the PSG. You can also change the clock signal phase so the clock occurs during the valid portion of the data. Figure 12- 14 shows the clock setup menu.
Peripheral Devices N5102A Digital Signal Interface Module This error is reported when the output FIFO is overflowing in the digital module. This error can be generated if an external clock or its reference is not set up properly, or if the internal VCO is unlocked. 806 Digital module output FIFO underflow error; There are not enough samples being produced for the current clock rate. Verify that the digital module clock is set up properly.
Peripheral Devices N5102A Digital Signal Interface Module Table 12-8 Clock Source Settings and Connectors Clock Source Softkeys Reference Frequency N5102A Module Connection Clock Ratea External • Device • Internalb • • Freq Ref Ext Clock In Device Interface • • • a.For the Internal selection, this sets the internal clock rate. For the External and Device selections, this tells the interface module the rate of the applied clock signal. b.
Peripheral Devices N5102A Digital Signal Interface Module Generating Digital Data Press the N5102A Off On softkey to On. Digital data is now being transferred through the N5102A module to the device. The green status light should be blinking. This indicates that the data lines are active. If the status light is solidly illuminated (not blinking), all the data lines are inactive.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-15 First-Level Softkey Menu Internal clock going to the DUT Line is grayed out until the N5102A module interface is turned on Selecting the Input Direction If both Option 003 (output mode) and Option 004 (input mode) are installed, you must select the input direction. Press Data Setup > Direction Input Output to Input and press Return.
Peripheral Devices N5102A Digital Signal Interface Module Choosing the Logic Type and Port Configuration Figure 12-16 Logic and Port Configuration Softkey Menus 1. Refer to Figure 12- 16. Press the Logic Type softkey. From this menu, choose a logic type. CAUTION Changing the logic type can increase or decrease the signal voltage level. To avoid damaging the device and/or the N5102A module, ensure that both are capable of handling the voltage change. 2.
Peripheral Devices N5102A Digital Signal Interface Module Configuring the Clock Signal 1. Press the Clock Setup softkey, as shown in Figure 12- 17. Figure 12-17 Clock Setup Menu Location Accesses the Clock Setup Menu From this softkey menu, set all of the clock parameters that synchronize the data between the N5102A module and the device. From this menu, the clock signal phase can be changed so the clock occurs during the valid portion of the data. Figure 12- 18 shows the clock setup menu.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-18 Clock Setup Softkey Menu for a Parallel Port Configuration Inactive for Input mode Inactive for clock rates below 25 MHz Active for only the Internal clock source selection Inactive for clock rates below 10 MHz and above 200 MHz The top graphic on the display shows the current clock source that provides the output clock signal at the Clock Out and Device Interface connectors.
Peripheral Devices N5102A Digital Signal Interface Module For the External selection, the signal is supplied by an external clock source and applied to the Ext Clock In connector. For the Device selection, the clock signal is supplied through the Device Interface connector, generally by the device being tested. If Internal is Selected Using an external frequency reference, the N5102A module generates its own internal clock signal.
Peripheral Devices N5102A Digital Signal Interface Module The skew has discrete values with a range that is dependent on the clock rate. Refer to “Clock Timing for Phase and Skew Adjustments” on page 251 for more information on skew settings. 8. Enter the skew adjustment that best positions the clock with the valid portion of the data. 9. Press the Clock Polarity Neg Pos softkey to Neg. This shifts the clock signal 180 degrees, so that the data starts during the negative clock transition.
Peripheral Devices N5102A Digital Signal Interface Module Figure 12-20 Data Setup Softkey Menu with Parallel Port Configuration Inactive for a serial port configuration Frame polarity is active for a serial port configuration Only available when the N5102A digital module is turned on Only available when data type is Pre-FIR Samples 2. Press the Data Type softkey. In this menu, select the data type to be either filtered (Samples) or unfiltered (Pre-FIR Samples).
Peripheral Devices Millimeter-Wave Source Modules 6. Press the More (1 of 2) softkey. From this softkey menu, select the bit order, swap I and Q, the polarity of the data, and access menus that provides data negation, scaling, and filtering parameters. 7. Press the Data Negation softkey. Negation differs from changing the I and Q polarity.
Peripheral Devices Millimeter-Wave Source Modules The following is a list of equipment required for extending the frequency range of the signal generator: • Agilent 8355x series millimeter- wave source module • Agilent 8349B microwave amplifier (required only for the E8257D PSG without Options 1EA, 1EU, or 521) • RF output cables and adapters as required NOTE Maximum insertion loss for cables and adapters connected to the E8267D PSG or E8257D PSG with Options 1EA, 1EU, or 521, should be less than 1.5 dB.
Peripheral Devices Millimeter-Wave Source Modules Figure 12-21 274 E8257D PSG without Option 1EA, 1EU, or 521 Chapter 12
Peripheral Devices Millimeter-Wave Source Modules Figure 12-22 Setup for E8267D PSG and E8257D PSG with Option 1EA, 1EU, or 521 Configuring the Signal Generator 1. Turn on the signal generator’s line power. NOTE Refer to the mm- wave source module specifications for the specific frequency and amplitude ranges. 2. Press Frequency > (3 of 3) > Source Module, toggle the Agilent 8355x Source Module Off On softkey to On.
Peripheral Devices Millimeter-Wave Source Modules When the 8355x series mm- wave source is enable via the front panel Agilent 8355x Source Module Off On softkey, the MMOD indicator in the FREQUENCY area and the MM indicator in the AMPLITUDE area will appear on the signal generator’s display. 3. If the RF OFF annunciator is displayed, press RF On/Off. Leveled power should be available at the output of the millimeter- wave source module.
Peripheral Devices Millimeter-Wave Source Modules Figure 12-23 E8257D PSG without Option 1EA, 1EU, or 521 Figure 12-24 Setup for E8267D PSG and E8257D PSG with Option 1EA, 1EU, or 521 Chapter 12 277
Peripheral Devices Millimeter-Wave Source Modules Configuring the Signal Generator The following procedure configures a PSG for use with any external source module that has a WR (waveguide rectangular) frequency range of 90- 140 GHz. You can modify the frequency range to match your source module. 1. Turn on the signal generator’s line power. NOTE Automatic leveling at the source module output is not available with the OEM Source Module selection. 2. Press Frequency > (3 of 3) > Source Module.
13 Troubleshooting This chapter provides basic troubleshooting information for Agilent PSG signal generators. If you do not find a solution here, refer to the Agilent PSG Signal Generators Service Guide. NOTE If the signal generator displays an error, always read the error message text by pressing Utility > Error Info.
Troubleshooting RF Output Power Problems RF Output Power too Low NOTE On E8267D’s, an –222 Data out of range (“output power”) error can be caused by: • An incorrect waveform RMS voltage when using the signal generator with the ALC off. • The marker signal is not routed correctly to the ALC hold and the pulse modulator for complex wireless signals. For these instrument setups, if the signal is unleveled, the instrument does not have sufficient power available. 1.
Troubleshooting RF Output Power Problems Figure 13-1 Effects of Reverse Power on ALC SIGNAL GENERATOR OUTPUT CONTROL ALC LEVEL = – 8 dBm RF OUTPUT = – 8 dBm MIXER RF LEVEL CONTROL DETECTOR MEASURES – 8 dBm ALC LEVEL LO DETECTOR MEASURES – 5 dBm REVERSE POWER LO FEEDTHRU = – 5 dBm LO LEVEL = +10 dBm IF The internally leveled signal generator RF output (and ALC level) is –8 dBm. The mixer is driven with an LO of +10 dBm and has an LO–to–RF isolation of 15 dB.
Troubleshooting RF Output Power Problems Figure 13-2 Reverse Power Solution SIGNAL GENERATOR OUTPUT CONTROL ALC LEVEL/ RF OUTPUT = +2 dBm RF INPUT = – 8 dBm 10 dB ATTEN RF LEVEL CONTROL DETECTOR MEASURES +2 dBm ALC LEVEL MIXER DETECTOR MEASURES – 15 dBm REVERSE POWER LO LO LEVEL = +10 dBm LO FEEDTHRU = – 5 dBm IF Compared to the original configuration, the ALC level is 10 dB higher while the attenuator reduces the LO feedthrough (and the RF output of the signal generator) by 10 dB.
Troubleshooting RF Output Power Problems 4. Turn the RF on: set RF On/Off to On 5. Turn the signal generator’s automatic leveling control (ALC) off: press Amplitude > ALC Off On to Off. 6. Monitor the RF output amplitude as measured by the power meter. Press Amplitude and adjust the signal generator’s RF output amplitude until the desired power is measured by the power meter.
Troubleshooting RF Output Power Problems This executes the manual fixed power search routine, which is the default mode. Setting the Power Search Reference (E8267D only) NOTE A successful power search is dependent on a valid power search reference. Additionally, on the E8267D, there are up to four Power Search Reference modes: ARB RMS, Fixed, Manual RMS or Manual, and Modulated. These four reference modes select the reference voltage used while the RF signal is being I/Q modulated.
Troubleshooting No Modulation at the RF Output DC bias is removed and the I/Q signal is reapplied to the I/Q modulator. The RMS voltage value can be found in the waveform header (Refer to Chapter 3, “Basic Digital Operation.”) The RMS voltage value can be set by the user or calculated by the signal generator. NOTE The ARB RMS softkey is only available when the internal Arb is enabled. Fixed During Fixed, the Power Search Reference is set fixed RMS reference level and is used to bias the I/Q modulator.
Troubleshooting Sweep Problems Sweep Problems Sweep Appears to be Stalled The current status of the sweep is indicated as a shaded rectangle in the progress bar. You can observe the progress bar to determine if the sweep is progressing.
Troubleshooting Data Storage Problems If the list dwell values are correct, continue to the next step. 4. Observe if the Dwell Type List Step softkey is set to Step. When Step is selected, the signal generator will sweep the list points using the dwell time set for step sweep rather than the sweep list dwell values. To view the step sweep dwell time, follow these steps: a. Press Configure Step Sweep. b. Observe the value set for the Step Dwell softkey.
Troubleshooting Cannot Turn Off Help Mode Cannot Turn Off Help Mode 1. Press Utility > Instrument Info/Help Mode 2. Press Help Mode Single Cont until Single is highlighted. The signal generator has two help modes; single and continuous. When you press Help in single mode (the factory preset condition), help text is provided for the next key you press. Pressing another key will exit the help mode and activate the key’s function.
Troubleshooting Error Messages CAUTION Carefully read the entire message! It may list additional risks with this procedure. 3. Release the Preset key. 4. To continue with the sequence, press Continue (to abort with no lost files, press Abort). 5. When the sequence concludes, do the following: a. Cycle power. Cycling power restores all previously installed options. Because calibration files are restored from EEPROM, you should see several error messages. b. Perform the DCFM/DCM calibration.
Troubleshooting Error Messages Error Message File A complete list of error messages is provided in the file errormessages.pdf, on the CDROM supplied with your instrument. In the error message list, an explanation is generally included with each error to further clarify its meaning. The error messages are listed numerically. In cases where there are multiple listings for the same error number, the messages are in alphabetical order.
Troubleshooting Contacting Agilent Sales and Service Offices The string for a positive error is not defined by SCPI. A positive error indicates that the instrument detected an error within the GPIB system, within the instrument’s firmware or hardware, during the transfer of block data, or during calibration. Execution Errors (–299 to –200) indicate that an error has been detected by the instrument’s execution control block.
Troubleshooting Returning a Signal Generator to Agilent Technologies packaging to properly protect the signal generator.
Index Symbols M 17, 153 Numerics 003, option 4 004, option 4 005, option 4 007, option 2, 5, 7, 49 008, option 2, 5 009, option 4 015, option 4 016, option 4 1 GHz REF OUT connector 27 10 MHz EFC connector 28 10 MHz IN connector 29 10 MHz OUT connector 30 128QAM I/Q modulation, creating 172 1410, application note 221, 231 1E1, option 2, 5 1EA, option 2, 5 1ED, option 2, 5 1EH, option 2, 5, 44 1EM, option 2, 5 1EU, option 2, 5 1SM, option 2, 5 2’s complement description 259, 271 27 kHz pulse 46 403,option 9
Index arb 79 ARMED annunciator 17 arrow hardkeys 13 ATTEN HOLD annunciator 17 attenuator, external leveling 133 AUTOGEN_WAVEFORM file 91 automatic leveling control.
Index common frequency reference 245 connectors external triggering 114 external triggering source 115 front panel 9 rear panel 20 continuous list sweep 49 step sweep 47 triggering 113 continuous wave configuring 42 description 7 contrast adjustments 14 correction array (user flatness) configuration 136 load from step array 137 viewing 137 See also user flatness correction couplers/splitters, using 130 custom arb 80 custom arb waveform generator 8, 159–179 custom mode 79 custom real-time I/Q baseband 8, 181
Index display blanking 73 contrast decrease 14 contrast increase 14 descriptions 16 overview 16 secure 73 DMOD files 61 documentation options 6 documentation, list of xiii downloading firmware 6 dual arb 79 dual ARB player 8, 91–96 Dual ARB real-time noise 95 dual arbitrary waveform generator 8, 91–96 dwell time 46 E E8257D optional features 2 E8267D optional features 4 standard features 3 E8663D optional features 5 Edit Item softkey 39 Erase All 70, 71, 73 erase and overwrite 70 erase and sanitize 70 erasi
Index using LAN 6 using RS-232 6 Flash Drive Input Connector 35 flatness correction. See user flatness correction FM 18, 152 formula, skew discrete steps 251 framed data 112 free run trigger response 113 frequency display area 17 hardkey 10 modulation.
Index troubleshooting 287 using 63 See also memory catalog instrument states 55 int gated 154 interface connectors AUXILIARY INTERFACE 29 GPIB 28 LAN 29 RS-232 29 interface, remote 139 intermodulation distortion how to minimize 119 testing non-linear devices 221, 231 internal simultaneous triggering pulse source 155 internal clock source selection 262, 268 interpolation filter 125–126 IQ clock rates 242 modulation 177 IQ modulation 177 K key, license 74 keypad, numeric 12 keys disabling 73 front panel 9–14
Index waveform 66 writing to 65 menus marker 101 marker polarity 111 trigger 113 MENUS hardkeys 11 microwave amplifier 273, 276 Millimeter 272 millimeter-wave source module 272 mixer, signal loss while using 280 mm-source 59 mm-wave source module extending frequency range with 272 leveling with 133 user flatness correction array, creating 140–146 mod on/off 18 Mod On/Off hardkey 12 models, signal generator 1 modes of operation 7 modes, triggering 112 modulation amplitude.
Index NVWFM files 61 Nyquist filters 163, 164 O OFDM 130 offset 43, 44, 153 offset binary use 259, 271 on/off switch 14 operation basics 37 digital basics 79 modes of 7 Optimize Signal-to-Noise ratio softkey 45 Option 422 201 options 003 4 004 4 005 4 007 2, 5, 7, 49 008 2, 5 009 4 015 4, 26, 27, 177 016 4, 26, 27, 177 1E1 2, 5 1EA 2, 5 1ED 2, 5 1EH 2, 5, 44 1EM 2, 5 1EU 2, 5 1SM 2, 5 403 95 403/403 description 4 409, GPS 210 424, GPS 210 424, MSGPS 202 521 2, 5 601/602 basic digital operation 79 custom arb
Index marker setting, saving 81 markers 111 trigger, external 114 port configuration, selecting 256 power meter 135, 282 output, troubleshooting 280 peaks 117–123 receptacle, AC 28 search mode 283 supply troubleshooting 280 switch 14 PRAM 79 predefined filters 162 predefined modulation setups 159, 181 pre-fir samples selection 259, 271 Preset hardkey 14 private data 65 problems.
Index leveling, external 130–133 limit, setting 40 mm-wave source module, using 272 sweeping 45 troubleshooting 279 user flatness correction 133–146 rise delay, burst shape 188 rise time, burst shape 188 root Nyquist filters 163, 164 routing, marker ALC hold 98 RF blanking 109 saving settings 98 settings, saving 81 RS-232 connector 29 runtime scaling 127 S S (service request) annunciator 18 sample rates 239 rates, parallel/parallel intrlvd port configuration 242 rates, serial port configuration 241 type sel
Index available for PSG 1 options 6 source module 272 source module interface 31 SOURCE SETTLED connector 31 source, external trigger 113 spectral regrowth 119 spectrum analyzer, troubleshooting signal loss 282 square pulse 46 standby LED 14 state files 61 state registers 55 step array (user flatness) 135 See also user flatness correction step attenuator, external leveling 133 step sweep 46–47 STOP SWEEP IN/OUT connector 30 storage, troubleshooting 287 subframe indicator, GPS 213 sweep 27 kHz pulse 46 8757D
Index V vector PSG optional features 4 standard features 3 VIDEO OUT connector 13 volatile memory 91 W warranted logic output clock rates 240 waveform memory 66, 69 waveforms analog modulation 151 ARB file headers 80–90 CCDF curve 123–124 clipping 117–125 custom 159–179 custom real-time I/Q baseband 181–200 DAC over-range errors 125–127 file catalogs 61 interpolation 125–126 markers 96 multicarrier 159, 161, 178 multitone 221–229 player, dual ARB 91–96 samples 125–126 scaling 125–127 segments 92–96 sequence
