User’s Guide Agilent Technologies PSG Signal Generators This guide applies to the following signal generator models: E8267C PSG Vector Signal Generator E8257C PSG Analog Signal Generator E8247C PSG CW Signal Generator Due to our continuing efforts to improve our products through firmware and hardware revisions, signal generator design and operation may vary from descriptions in this guide. We recommend that you use the latest revision of this guide to ensure you have up-to-date product information.
Notice The material contained in this document is provided “as is”, and is subject to being changed, without notice, in future editions. Further, to the maximum extent permitted by applicable law, Agilent disclaims all warranties, either express or implied with regard to this manual and to any of the Agilent products to which it pertains, including but not limited to the implied warranties of merchantability and fitness for a particular purpose.
Contents 1. Signal Generator Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Signal Generator Models and Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 E8247C PSG CW Signal Generator Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 E8257C PSG Analog Signal Generator Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents 30. Display Contrast Increase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 31. Local . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 32. Preset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 33. I/Q INPUTS . . . . . . . . . . . . . . . . . . . . . . . .
Contents 22. Q OUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 23. Q-bar OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 24. BASEBAND GEN REF IN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 25. SMI (SOURCE MODULE INTERFACE) . . . . . . . . . . . . . . . . . . . . . . . . .
Contents 4. Analog Modulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Analog Modulation Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Configuring AM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 To Set the Carrier Frequency . . . . . . . . . . . . . . . . . . . . .
Contents Editing a Waveform Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102 Storing and Loading Waveform Segments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103 Renaming a Waveform Segment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103 Using Waveform Markers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents To Set the ARB Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 7. Custom Real Time I/Q Baseband . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Working with Predefined Setups (Modes) . . . . . . . . . . . . . . . . . . . .
Contents To View a Two-Tone Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182 To Minimize Carrier Feedthrough. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .184 To Change the Alignment of a Two-Tone Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186 10. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1 Signal Generator Overview In the following sections, this chapter describes the models, options, and features available for Agilent PSG signal generators. The modes of operation, front panel user interface, as well as front and rear panel connectors are also described.
Signal Generator Overview Signal Generator Models and Features Signal Generator Models and Features Table 1-1 lists the available PSG signal generator models along with their output signal types and frequency range.
Signal Generator Overview Signal Generator Models and Features E8257C PSG Analog Signal Generator Features An E8257C PSG analog signal generator provides all the functionality of an E8247C PSG CW signal generator and adds the following features: • open-loop or closed-loop AM • dc-synthesized FM to 10 MHz rates; maximum deviation depends on the carrier frequency • phase modulation (ΦM) • pulse modulation • external modulation inputs for AM, FM, ΦM, and pulse • simultaneous modulation configuratio
Signal Generator Overview Options E8267C PSG Vector Signal Generator Features An E8267C PSG vector signal generator provides all the functionality of an E8257C PSG analog signal generator, and adds the following features: • internal I/Q modulator • external analog I/Q inputs • single-ended and differential analog I/Q outputs Options PSG signal generators have hardware, firmware, software, and documentation options.
Signal Generator Overview Modes of Operation Modes of Operation All PSG signal generator models can be used in CW mode: • CW mode produces a single carrier signal. — If you have an E8247C PSG CW signal generator, you can produce a CW single carrier signal without modulation.
Signal Generator Overview Front Panel Front Panel Figure 1-1 shows the E8267C PSG vector signal generator front panel with a list of items called out that enable you to define, monitor, and manage input and output characteristics. The description of each item also applies to both the E8257C PSG analog signal generator and the E8247C PSG CW signal generator front panels.
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 13. 2. Softkeys Softkeys activate the displayed function to the left of each key. 3.
Signal Generator Overview Front Panel 8. Trigger 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 (E8257C and E8267C only) accepts a ±1Vp signal for AM, FM, and ΦM. With AM, FM, or ΦM, ±1 Vp produces the indicated deviation or depth. When ac-coupled inputs are selected for AM, FM, or ΦM and the peak input voltage differs from 1Vp by more than 3%, the HI/LO annunciators light on the display. The input impedance is selectable as either 50Ω or 600Ω and damage levels are 5 Vrms and 10 Vp.
Signal Generator Overview Front Panel 18. RF OUTPUT This connector is the output for RF and microwave signals. The nominal output impedance is 50Ω. The reverse-power damage levels are 0 Vdc, 0.5 watts nominal. On signal generators with Option 1EM, this output is relocated to a rear panel female BNC connector. 19. SYNC OUT This female BNC output connector (E8257C and E8267C only) outputs a synchronizing TTL-compatible pulse signal that is nominally 50 ns wide during internal and triggered pulse modulation.
Signal Generator Overview Front Panel 10Vp. The nominal input impedance is 50Ω. On signal generators with Option 1EM, this input is relocated to the rear panel. 26. Arrows These up and down arrow hardkeys are used to increase or decrease a numeric value, step through displayed lists, or to select items in a row of a displayed list. Individual digits or characters may be highlighted using the left and right arrow hardkeys.
Signal Generator Overview Front Panel 33. I/Q INPUTS These female BNC input connectors (E8267C only) accept an externally supplied, analog, I/Q modulation; the in-phase component is supplied through the I INPUT; the quadrature-phase component is supplied through the Q INPUT. The signal level is = 0.5 Vrms for a calibrated output level. The nominal input impedance is 50Ω or 600Ω. The damage level is 1 Vrms and 10 Vpeak.
Signal Generator Overview Front Panel Display Front Panel Display Figure 1-2 shows the front panel display. The LCD screen displays data fields, annotations, key press results, softkey labels, error messages, and annunciators that represent various active signal generator functions. Figure 1-2 1. Active Entry Area Front Panel Display Diagram 2. Frequency Area 6. Error Message Area 3. Annunciators 7. Text Area 4. Digital Modulation Annunciators 5. Amplitude Area 8. Softkey Label Area 1.
Signal Generator Overview Front Panel Display 3. Annunciators The display annunciators show the status of some of the signal generator functions and indicate any error conditions. An annunciator position may be used by more than one function. This does not create a problem, because only one function that shares an annunciator position can be active at a time. ΦM This annunciator (E8257C and E8267C only) appears when phase modulation is on. If frequency modulation is on, the FM annunciator replaces ΦM.
Signal Generator Overview Front Panel Display MOD ON/OFF This annunciator (E8257C and E8267C only) which is always present on the display, indicates whether active modulation formats have been enabled or disabled with the Mod On/Off hardkey. Pressing the Mod On/Off hardkey enables or disables all active modulation formats (AM, FM, ΦM, Pulse, or I/Q) that are applied to the output carrier signal available through the RF Output connector.
Signal Generator Overview Front Panel Display This annunciator appears when any of the phase locked loops are unable to maintain phase lock. You can determine which loop is unlocked by examining the error messages. UNLOCK 4. Digital Modulation Annunciators All digital modulation annunciators (E8267C PSG with Option 002/602 only) appear in this location. These annunciators appear only when the modulation is active, and only one digital modulation can be active at any given time.
Signal Generator Overview Rear Panel Rear Panel The signal generator rear panel (Figure 1-3) provides input, output, and remote interface connections. Descriptions are provided for each rear panel connector. When Option 1EM is added, all front panel connectors are moved to the real panel; for a description of these connectors, see “Front Panel” on page 6. Figure 1-3 Rear Panel Diagram 16. Digital Bus 17. WIDEBAND I INPUT 15. AUXILIARY I/O 18. WIDEBAND Q INPUT 20. I OUT 21. I-bar OUT 19. COH 22.
Signal Generator Overview Rear Panel 1. AC Power Receptacle The ac line voltage is connected here. The power cord receptacle accepts a three-pronged power cable that is shipped with the signal generator. 2. GPIB This GPIB interface allows listen and talk capability with compatible IEEE 488.2 devices. 3. 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 5. 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 0V) output during sweep retrace and band-cross intervals. It provides high level (nominally +5V) output during the forward portion of sweep. Sweep stops when this input/output connector is grounded externally. 6.
Signal Generator Overview Rear Panel 11. EVENT 1 This female BNC connector (E8267C only) is used with an internal baseband generator (Option 002/602); on signal generators without Option 002/602, 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.
Signal Generator Overview Rear Panel 15. AUXILIARY I/O This female 37-pin connector (E8267C only) is active only on instruments with an internal baseband generator (Option 002/602); on signal generators without Option 002/602, this connector is non-functional. This connector provides access to the inputs and outputs described in the following figure. Figure 1-5 View looking into rear panel connector Auxiliary I/O Connector (Female 37-Pin) Used with an internal baseband generator.
Signal Generator Overview Rear Panel 16. Digital Bus This is a proprietary bus used for Agilent Baseband Studio products, which require an E8267C with Option 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 www.agilent.com/find/basebandstudio).
Signal Generator Overview Rear Panel 21. I-bar OUT This female BNC connector (E8267C only) can be used with an internal baseband generator (Option 002/602) to output the complement of the analog, in-phase component of I/Q modulation; on signal generators without Option 002/602, this female BNC connector can be used to output the complement of the in-phase component of an external I/Q modulation that has been fed into the I input connector.
Signal Generator Overview Rear Panel 25. SMI (SOURCE MODULE INTERFACE) This interface is used to connect to compatible Agilent Technologies 83550 Series mm-wave source modules. 26. 10 MHz OUT This female BNC connector outputs a nominal signal level of > +4 dBm and has an output impedance of 50Ω. The accuracy is determined by the timebase used. 27. 10 MHz IN This female BNC connector accepts an external timebase reference input signal level of >−3 dBm. The reference must be 1, 2, 2.
2 Basic Operation In the following sections, this chapter describes operations common to all Agilent PSG signal generators: • “Using Table Editors” on page 26 • “Configuring a Continuous Wave RF Output” on page 28 • “Configuring a Swept RF Output” on page 31 • “Using Ramp Sweep (Option 007)” on page 37 • “Extending the Frequency Range with a mm-Wave Source Module” on page 47 • “Turning On a Modulation Format” on page 50 • “Applying a Modulation Format to the RF Output” on page 51 • “Using D
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 Configuring the RF Output Configuring the RF Output This section provides information on how to create continuous wave and swept RF (on page 31) outputs. It also has information on using a mm-Wave source module to extend the signal generator’s frequency range (see page 47).
Basic Operation Configuring the RF Output 6. Press the up arrow key. Each press of the up arrow key increases the frequency by the increment value last set with the Incr Set hardkey. The increment value is displayed in the active entry area. 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.
Basic Operation Configuring the RF Output Setting the RF Output Amplitude 1. Preset the signal generator: Press Preset. The AMPLITUDE area of the display shows the minimum power level of the signal generator. This is the normal preset RF output amplitude. 2. Turn on the RF output: Press RF On/Off. The display annunciator changes to RF ON. At the RF OUTPUT connector, the RF signal is output at the minimum power level. 3. Change the amplitude to −20 dBm: Press Amplitude > −20 > dBm.
Basic Operation Configuring the RF Output Configuring a Swept RF Output A PSG signal generator has up to three sweep types: step sweep, list sweep, and ramp sweep (Option 007). NOTE List sweep data cannot be saved within an instrument state, but can be saved to the memory catalog. For instructions on saving list sweep data, see “Storing Files to the Memory Catalog” on page 53.
Basic Operation Configuring the RF Output Using Step Sweep Step sweep provides a linear progression through the start-to-stop frequency and/or amplitude values. You can toggle the direction of the sweep, up or down. When the Sweep Direction Down Up softkey is set to Up, values are swept from the start amplitude/frequency to the stop amplitude/frequency. When set to Down, values are swept from the stop amplitude/frequency to the start amplitude/frequency.
Basic Operation Configuring the RF Output 11. Press Return > Sweep > Freq & Ampl. This sets the step sweep to sweep both frequency and amplitude data. Selecting this softkey returns you to the previous menu and turns on the sweep function. 12. Press RF On/Off. The display annunciator changes from RF OFF to RF ON. 13. Press Single Sweep. A single sweep of the frequencies and amplitudes configured in the step sweep is executed and available at the RF OUTPUT connector.
Basic Operation Configuring the RF Output Using List Sweep List sweep enables you to create a list of arbitrary frequency, amplitude, and dwell time values and sweep the RF output based on the entries in the List Mode Values table. Unlike a step sweep that contains linear ascending/descending frequency and amplitude values, spaced at equal intervals throughout the sweep, list sweep frequencies and amplitudes can be entered at unequal intervals, nonlinear ascending/descending, or random order.
Basic Operation Configuring the RF Output To Edit List Sweep Points 1. Press Return > Sweep > Off. Turning the sweep off allows you to edit the list sweep points without generating errors. If sweep remains on during editing, errors occur whenever one or two point parameters (frequency, power, and dwell) are undefined. 2. Press Configure List Sweep. This returns you to the sweep list table. 3. Use the arrow keys to highlight the dwell time in row 1. 4. Press Edit Item.
Basic Operation Configuring the RF Output To Configure a Single List Sweep 1. Press Return > Sweep > Freq & Ampl This turns the sweep on again. No errors should occur if all parameters for every point have been defined in the previous editing process. 2. Press Single Sweep. The signal generator will single sweep the points in your list. The SWEEP annunciator activates during the sweep. 3. Press More (1 of 2) > Sweep Trigger > Trigger Key.
Basic Operation Configuring the RF Output Using Ramp Sweep (Option 007) Ramp sweep provides a linear progression through the start-to-stop frequency and/or amplitude values. Ramp sweep is much faster than step or list sweep, and is designed to work with an 8757D scalar network analyzer. This section describes the ramp sweep capabilities available in PSG signal generators with Option 007. You will learn how to use basic ramp sweep, and how to configure a ramp sweep for a master/slave setup (see page 45).
Basic Operation Configuring the RF Output Configuring a Frequency Sweep 1. Set up the equipment as shown in Figure 2-2. NOTE Figure 2-2 The PSG signal generator is not compatible with the GPIB system interface of an 8757A, 8757C, or 8757E. For these older scalar network analyzers, do not connect the GPIB cable in Figure 2-2. This method provides only a subset of 8757D functionality. See the PSG Data Sheet for details. Use the 8757A/C/E documentation instead of this procedure. Equipment Setup 2.
Basic Operation Configuring the RF Output 6. Preset either instrument. Presetting one of the instruments should automatically preset the other as well. If both instruments do not preset, check the GPIB connection, GPIB addresses, and ensure the 8757D is set to system interface mode (SYSINTF set to ON). The PSG automatically activates a 2 GHz to maximum frequency ramp sweep with a constant amplitude of 0 dBm. Notice that the RF ON, SWEEP, and PULSE annunciators appear on the PSG display.
Basic Operation Configuring the RF Output Figure 2-3 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 4. Move the cursor back to marker 0 and press Delta Ref Set > Marker Delta Off On to On. In the table editor, notice that the frequency values for each marker are now relative to marker 0. Ref appears in the far right column (also labeled Ref) to indicate which marker is the reference. Refer to Figure 2-4. Figure 2-4 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.
Basic Operation Configuring the RF Output Figure 2-5 Delta Markers on 8757D 6. Press Turn Off Markers. All active markers turn off. Refer to the 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. Since ramp is the current sweep type, softkeys in this menu specifically control ramp sweep settings.
Basic Operation Configuring the RF Output 3. Press Sweep Time to Manual > 5 > sec. In auto mode, the sweep time automatically sets to the fastest allowable value. In manual mode, you can select any sweep time slower than the fastest allowable. The fastest allowable sweep time is dependent on the number of trace points and channels being used on the 8757D and the frequency span. 4. Press Sweep Time to Auto. The sweep time returns to its fastest allowable setting. Using Alternate Sweep 1.
Basic Operation Configuring the RF Output Figure 2-6 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 Configuring a Ramp Sweep for a Master/Slave Setup This procedure shows you how to configure two PSGs and an 8757D to work in a master/slave setup. 1. Set up the equipment as shown in Figure 2-7. Use a 9-pin, D-subminiature, male RS-232 cable with the pin configuration shown in Figure 2-8 on page 46 to connect the auxiliary interfaces of the two PSGs. You can also order the cable (part number 8120-8806) from Agilent Technologies.
Basic Operation Configuring the RF Output Figure 2-8 RS-232 Pin Configuration 2. Set up the slave PSG’s frequency and power settings. By setting up the slave first, you avoid synchronization problems. 3. Set up the master PSG’s frequency, power, and sweep time settings. The two PSGs can have different frequency and power settings for ramp sweep. 4. Set the slave PSG’s sweep time to match that of the master. Sweep times must be the same for both PSGs. 5. Set the slave PSG to continuous triggering.
Basic Operation Configuring the RF Output Extending the Frequency Range with a mm-Wave Source Module The RF output frequency of the signal generator can be multiplied using an Agilent 83550 Series millimeter-wave source module. The signal generator/mm-wave source module’s output is automatically leveled when the instruments are connected. The output frequency range depends on the specific mm-wave source module.
Basic Operation Configuring the RF Output Figure 2-9 Setup for E8247C PSG and E8257C PSG without Option 1EA Setting the Signal Generator 1. Turn on the signal generator’s line power.
Basic Operation Configuring the RF Output Figure 2-10 Setup for E8267C PSG or E8247C PSG and E8257C PSG with Option 1EA The MMMOD indicator in the FREQUENCY area and the MM indicator in the AMPLITUDE area of the signal generator’s display indicate that the mm-wave source module is active. NOTE Refer to the mm-wave source module specifications for the specific frequency and amplitude ranges. 2. If the RF OFF annunciator is displayed, press RF On/Off.
Basic Operation Modulating a Signal Modulating a Signal This section describes how to turn on a modulation format, and how to apply it to the RF output. Turning On a Modulation Format A modulation format can be turned on prior to or after setting the signal parameters. 1. Access the first menu within the modulation format. This menu displays a softkey that associates the format’s name with off and on. For example, AM > AM Off On.
Basic Operation Modulating a Signal 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.When the key is set to On, the MOD ON annunciator shows in the display, whether or not there is an active modulation format.
Basic Operation Using Data Storage Functions 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. Using the Memory Catalog The Memory Catalog is the signal generator’s interface for viewing, storing, and saving files; it can be accessed through the signal generator’s front panel or a remote controller. (For information on performing these tasks remotely, see the Programming Guide.
Basic Operation Using Data Storage Functions Storing Files to the Memory Catalog To store a file to the memory catalog, first create a file. For this example, use the default list sweep table. 1. Press Preset. 2. Press Sweep/List > Configure List Sweep > More (1 of 2) > Load/Store. This opens the “Catalog of List Files”. 3. Press Store to File. This displays a menu of alphabetical softkeys for naming the file. Store to: is displayed in the active function area. 4.
Basic Operation Using Data Storage Functions Using the Instrument State Register The instrument state register is a section of memory divided into 10 sequences (numbered 0 through 9) each containing 100 registers (numbered 00 through 99). It is used to store and recall instrument settings. It provides a quick way to reconfigure the signal generator when switching between different signal configurations.
Basic Operation Using Data Storage Functions Recalling an Instrument State Using this procedure, you will learn how to recall instrument settings saved to an instrument state register. 1. Press Preset. 2. Press the Recall hardkey. Notice that the Select Seq softkey shows sequence 1. (This is the last sequence that you used.) 3. Press RECALL Reg. The register to be recalled in sequence 1 becomes the active function. Press the up arrow key once to select register 1.
Basic Operation Using Data Storage Functions Deleting All Registers within a Sequence 1. Press Preset. 2. Press the Recall or Save hardkey. Notice that the Select Seq softkey shows the last sequence that you used. 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.
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 Enabling Options 4. Enable the software option: a. Highlight the desired option. b. Press Modify License Key, and enter the 12-character license key (from the license key certificate). 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.
3 Optimizing Performance In the following sections, this chapter describes procedures that improve the performance of the Agilent PSG signal generator. • Selecting ALC Bandwidth (below) • “Using External Leveling” on page 60 • “Creating and Applying User Flatness Correction” on page 64 • “Adjusting Reference Oscillator Bandwidth (Option UNR)” on page 76 Selecting ALC Bandwidth For internal leveling, the signal generator uses automatic leveling control (ALC) circuitry prior to the RF output.
Optimizing Performance Using External Leveling Using External Leveling The PSG signal generator can be externally leveled by connecting an external sensor at the point where leveled RF output power is desired. This sensor detects changes in RF output power and returns a compensating voltage to the signal generator’s ALC input. The ALC circuitry raises or lowers (levels) the RF output power based on the voltage received from the external sensor, ensuring constant power at the point of detection.
Optimizing Performance Using External Leveling 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 Determining the Leveled Output Power Figure 3-3 shows the input power versus output voltage characteristics for typical Agilent 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 Using External Leveling 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 Creating and Applying User Flatness Correction User flatness correction allows the digital adjustment of RF output amplitude for up to 1601 frequency points in any frequency or sweep mode. Using an Agilent E4416A/17A or E4418B/19B power meter (controlled by the signal generator through GPIB) to calibrate the measurement system, a table of power level corrections is created for frequencies where power level variations or losses occur.
Optimizing Performance Creating and Applying User Flatness Correction Configure the Power Meter 1. 2. 3. 4. Select SCPI as the remote language for the power meter. Zero and calibrate the power sensor to the power meter. Enter the appropriate power sensor calibration factors into the power meter as appropriate. Enable the power meter’s cal factor array. NOTE For operating information on a particular power meter/sensor, refer to its operating guide.
Optimizing Performance Creating and Applying User Flatness Correction 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. For E4417A and E4419B models, press Meter Channel A B to select the power meter’s active channel. d.
Optimizing Performance Creating and Applying User Flatness Correction Perform the User Flatness Correction NOTE If you are not using an Agilent E4416A/17A/18B/19B power meter, or if your power meter does not have a GPIB interface, you can perform the user flatness correction manually. For instructions, see “Performing the User Flatness Correction Manually” on page 67. 1. Press More (1 of 2) > User Flatness > Do Cal. This creates the user flatness amplitude correction value table entries.
Optimizing Performance Creating and Applying User Flatness Correction Save the User Flatness Correction Data to the Memory Catalog This process allows you to save the user flatness correction data as in the signal generator’s memory catalog. With several user flatness correction files saved to the memory catalog, any file can be recalled, loaded into the correction array, and applied to the RF output to satisfy specific RF output flatness requirements. 1. Press Load/Store. 2. Press Store to File. 3.
Optimizing Performance Creating and Applying User Flatness Correction Returning the Signal Generator to GPIB Listener Mode During the user flatness correction process, the power meter is slaved to the signal generator via GPIB, and no other controllers are allowed on the GPIB interface. The signal generator operates in GPIB talker mode, as a device controller for the power meter. In this operating mode, it cannot receive SCPI commands via GPIB.
Optimizing Performance Creating and Applying User Flatness Correction Required Equipment • Agilent 83554A millimeter-wave source module • Agilent E4416A/17A/18B/19B power meter • Agilent R8486A power sensor • Agilent 8349B microwave amplifier (required for signal generators without Option 1EA) • GPIB interface cable • adapters and cables as required NOTE The equipment setups in Figure 3-5 and Figure 3-6 assume that the steps necessary to correctly level the RF output have been followed.
Optimizing Performance Creating and Applying User Flatness Correction 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. 1. Turn off the line power to the signal generator. 2. Connect the equipment. For standard signal generators, use the setup in Figure 3-5. For Option 1EA signal generators, use the setup in Figure 3-6.
Optimizing Performance Creating and Applying User Flatness Correction Figure 3-6 NOTE User Flatness with mm-Wave Source Module and Option 1EA Signal Generator To ensure adequate RF amplitude at the mm-wave source module RF input when using Option 1EA signal generators, maximum amplitude loss through the adapters and cables connected between the signal generator’s RF output and the mm-wave source module’s RF input should be less than 1.5 dB. Configure the Signal Generator 1.
Optimizing Performance Creating and Applying User Flatness Correction 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. For E4417A and E4419B models, press Meter Channel A B to select the power meter’s active channel. d.
Optimizing Performance Creating and Applying User Flatness Correction 2. When prompted, press Done. This loads the amplitude correction values into the user flatness correction array. If desired, press Configure Cal Array. This opens the user flatness correction array, where you can view the list of defined frequencies and their calculated amplitude correction values.
Optimizing Performance Creating and Applying User Flatness Correction Save the User Flatness Correction Data to the Memory Catalog This process allows you to save the user flatness correction data as a file in the signal generator’s memory catalog. With several user flatness correction files saved to the memory catalog, specific files can be recalled, loaded into the correction array, and applied to the RF output to satisfy various RF output flatness requirements. 1. Press Load/Store. 2.
Optimizing Performance Adjusting Reference Oscillator Bandwidth (Option UNR) Adjusting Reference Oscillator Bandwidth (Option UNR) The reference oscillator bandwidth (sometimes referred to as loop bandwidth) in signal generators with Option UNR (improved close-in phase noise) is adjustable in fixed steps for either an internal or external 10 MHz frequency reference.
4 Analog Modulation In the following sections, this chapter describes the analog modulation capability in Agilent E8257C PSG Analog and E8267C PSG Vector Signal Generators.
Analog Modulation Analog Modulation Waveforms Analog Modulation Waveforms The signal generator can modulate the RF carrier with four types of analog modulation: • • • • amplitude, frequency, phase, and pulse.
Analog Modulation Configuring AM Configuring AM 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 FM Configuring FM In this example, you will learn how to create a frequency-modulated RF carrier. To Set the RF Output Frequency 1. Press Preset. 2. Press Frequency > 1 > GHz. To Set the RF Output Amplitude Press Amplitude > 0 > dBm. To Set the FM Deviation and Rate 1. Press the FM/ΦM hardkey. 2. Press FM Dev > 75 > kHz. 3. Press FM Rate > 10 > kHz.
Analog Modulation Configuring ΦM Configuring ΦM In this example, you will learn how to create a phase-modulated RF carrier. To Set the RF Output Frequency 1. Press Preset. 2. Press Frequency > 3 > GHz. To Set the RF Output Amplitude Press Amplitude > 0 > dBm. To Set the FM Deviation and Rate 1. Press the FM/ΦM hardkey. 2. Press the FM ΦM softkey. 3. Press FM Dev > .25 > pi rad. 4. Press FM Rate > 10 > kHz.
Analog Modulation Configuring Pulse Modulation Configuring Pulse Modulation In this example, you will learn how to create a pulse-modulated RF carrier. To Set the RF Output Frequency 1. Press Preset. 2. Press Frequency > 2 > GHz. To Set the RF Output Amplitude Press Amplitude > 0 > dBm. To Set the Pulse Period and Width 1. Press Pulse > Pulse Period > 100 > usec. 2. Press Pulse > Pulse Width > 24 > usec.
Analog Modulation Configuring the LF Output Configuring the LF Output The signal generator has a low frequency (LF) output (described on page 9). The LF output’s source can be switched between Internal 1 Monitor, Internal 2 Monitor, Function Generator 1, or Function Generator 2. Using Internal 1 Monitor or Internal 2 Monitor as the LF output source, the LF output provides a replica of the signal from the internal source that is being used to modulate the RF output.
Analog Modulation Configuring the LF Output To Configure the LF Output with an Internal Modulation Source In this example, the internal FM modulation is the LF output source. NOTE Internal modulation (Internal Monitor) is the default LF output source. Configuring the Internal Modulation as the LF Output Source 1. Press Preset. 2. Press the FM/ΦM hardkey. 3. Press FM Dev > 75 > kHz. 4. Press FM Rate > 10 > kHz. 5. Press FM Off On.
Analog Modulation Configuring the LF Output 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.
Analog Modulation Configuring the LF Output 86 Chapter 4
5 Dual Arbitrary Waveform Generator In the following sections, this chapter describes the Dual Arb mode, which is available only in E8267C PSG vector signal generators with Option 002/602: • “Arbitrary (ARB) Waveform File Headers” on page 88 • “Using the Dual ARB Waveform Player” on page 99 • “Using Waveform Clipping” on page 112 • “Waveform Clipping Concepts” on page 113 • “Using Waveform Markers” on page 104 • “Waveform Marker Concepts” on page 108 • “Using Waveform Triggers” on page 111 8
Dual Arbitrary Waveform Generator Arbitrary (ARB) Waveform File Headers Arbitrary (ARB) Waveform File Headers An ARB waveform file header enables you to save instrument setup information (key format settings) along with a waveform. When you retrieve a stored waveform, the header information is applied so that when the waveform starts playing, the dual ARB player is set up the same way each time. Headers can also store a user-specified 32-character description of the waveform or sequence file.
Dual Arbitrary Waveform Generator Arbitrary (ARB) Waveform File Headers Creating a File Header for a Modulation Format Waveform When you turn on a modulation format, the PSG generates a temporary waveform file (AUTOGEN_WAVEFORM), with a default file header. The default header has no signal generator settings saved to it. This procedure, which is the same for all ARB formats, demonstrates how to create a file header for a Custom digital modulation format. 1. Preset the signal generator. 2.
Dual Arbitrary Waveform Generator Arbitrary (ARB) Waveform File Headers Modifying Header Information in a Modulation Format This procedure builds on the previous procedure, explaining the different areas of a file header, and showing how to access, modify, and save changes to the information. In a modulation format, you can access a file header only while the modulation format is active (on). In this procedure, we work within the Custom digital modulation format.
Dual Arbitrary Waveform Generator Arbitrary (ARB) Waveform File Headers 2. Save the information in the Current Inst. Settings column to the file header: Press Save Setup To Header. The same settings are now displayed in both the Saved Header Settings column and the Current Inst. Settings column. The settings in the Saved Header Settings column are the ones that have been saved in the file header.
Dual Arbitrary Waveform Generator Arbitrary (ARB) Waveform File Headers 3. Return to the ARB Setup menu: Press Return. This menu lets you change the current instrument settings. Figure 5-3 shows the ARB Setup softkey menu and 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.
Dual Arbitrary Waveform Generator Arbitrary (ARB) Waveform File Headers Figure 5-3 ARB Setup Softkey Menu and Marker Utilities Dual ARB Player softkey (it does not appear in the ARB formats) Chapter 5 93
Dual Arbitrary Waveform Generator Arbitrary (ARB) Waveform File Headers Figure 5-4 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 5-5 Saved File Header Changes Page 1 Page 2 94 Chapter 5
Dual Arbitrary Waveform Generator Arbitrary (ARB) Waveform File Headers Storing Header Information for a Dual ARB Player Waveform Sequence When you create a waveform sequence (described on page 101), 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).
Dual Arbitrary Waveform Generator 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.
Dual Arbitrary Waveform Generator 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 5-6). This task guides you through the available viewing choices. 1.
Dual Arbitrary Waveform Generator 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 be played back in only the dual ARB player. This is also true for downloaded waveform files (downloading files is described in the Programming Guide).
Dual Arbitrary Waveform Generator Using the Dual ARB Waveform Player Using the Dual ARB Waveform Player The dual arbitrary (ARB) waveform player is used to edit and play waveform files. There are two types of waveform files: segments (WFM1) and sequences (SEQ). A segments is an individual waveform that is defined using an installed ARB format, such as Two Tone, and created using the internal arbitrary waveform generator. A sequences is several individual segments strung together in one file.
Dual Arbitrary Waveform Generator 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 remote interface or generate a waveform using one of the ARB modulation formats. For information on downloading waveforms via remote interface, see the Programming Guide.
Dual Arbitrary Waveform Generator Using the Dual ARB Waveform Player Generating the Second Waveform Use the following steps to generate a new multitone waveform with nine tones. During waveform generation, the M-TONE and I/Q annunciators activate. The waveform is stored in volatile memory with the default file name AUTOGEN_WAVEFORM. 1. Press Mode > Multitone > Initialize Table > Number Of Tones > 9 > Enter > Done. 2. Generate the waveform: press Multitone Off On to On. 3.
Dual Arbitrary Waveform Generator Using the Dual ARB Waveform Player Playing a Waveform You can play a waveform sequence or a waveform segment using this procedure. Both waveform types follow the same process. This example plays a waveform sequence. If you have not created waveform segments and used them to build and store a waveform sequence, complete the steps in the previous procedures, “Creating Waveform Segments” on page 100, “Building and Storing a Waveform Sequence” on page 101.
Dual Arbitrary Waveform Generator Using the Dual ARB Waveform Player You have now changed the number of repetitions for each waveform segment entry from 1 to 100 and 200, respectively. The sequence has been stored under a new name to the Catalog of Seq Files in the signal generator’s memory catalog. To play the waveform sequence, refer to “Playing a Waveform” on page 102.
Dual Arbitrary Waveform Generator Using Waveform Markers Using Waveform Markers Waveform markers provide auxiliary output signals that are synchronized with a waveform segment. You can place up to four markers on a waveform segment. However, only Marker 1 and Marker 2 can be placed using the waveform player’s user interface (for more information, refer to “Waveform Marker Concepts” on page 108).
Dual Arbitrary Waveform Generator Using Waveform Markers To Place Repetitively Spaced Markers within a Waveform Segment If you have not created a waveform segment, complete the steps in the previous sections, “Generating the First Waveform” on page 100 and “Creating the First Waveform Segment” on page 100. 1. 2. 3. 4. 5. 6. 7. 8. Press Mode > Dual ARB > Waveform Segments. Press Load Store. Highlight a waveform segment (for example, TTONE).
Dual Arbitrary Waveform Generator Using Waveform Markers To Toggle Markers in an Existing Waveform Sequence In a waveform sequence, you can independently toggle the operating state of the markers on each waveform segment. When you build a waveform sequence, the markers on each segment are toggled to the last marker operating state that was used. In this example, you learn how to toggle markers within an existing waveform sequence.
Dual Arbitrary Waveform Generator Using Waveform Markers To Toggle Markers As You Create a Waveform Sequence You can combine waveform segments to create a waveform sequence while independently toggling the markers of each waveform segment. In this example, you learn how to toggle markers while building a waveform sequence. If you have not created waveform segments, complete the steps in the previous section, “Creating Waveform Segments” on page 100.
Dual Arbitrary Waveform Generator Using Waveform Markers Waveform Marker Concepts The Dual Arb mode of the signal generator has four markers that you can place on a waveform segment. Marker 1 and Marker 2 provide auxiliary output signals to the rear-panel EVENT 1 and EVENT 2 connectors, respectively. Markers 3 and 4 are available only for custom-programmed waveforms, and they provide auxiliary output signals to pins 19 and 18 of the rear-panel AUXILIARY I/O connector, respectively.
Dual Arbitrary Waveform Generator Using Waveform Markers Table 5-2 Marker 2 and EVENT 2 Marker File Bit 2 Signal At EVENT 2 Connector Waveform point n point n+1 point n+2 point n+3 ...
Dual Arbitrary Waveform Generator Using Waveform Markers Positive EVENT 2 ± Marker File Bit 2 Marker Polarity Marker 2 Blanks RF when Marker is Low Negative Marker 2 to RF Blank Off On A waveform sequence comprises waveform segments. When you combine segments to form a sequence, you can enable or disable Marker 1 and/or Marker 2 on a segment-by-segment basis.
Dual Arbitrary Waveform Generator Using Waveform Triggers Using Waveform Triggers The dual arbitrary waveform generator includes several different triggering options: single, gated, segment advance, and continuous. The trigger source can be the Trigger hardkey, a command sent through the remote interface, or an external signal applied to the TRIGGER IN rear panel connector.
Dual Arbitrary Waveform Generator Using Waveform Clipping Using Waveform Clipping Clipping limits power peaks in waveform segments by clipping the I and Q data to a selected percentage of its highest peak. Circular clipping is defined as clipping the composite I/Q data (I and Q data are equally clipped). Rectangular clipping is defined as independently clipping the I and Q data. For more information, see “Waveform Clipping Concepts” on page 113. In this section, you learn how to clip waveform segments.
Dual Arbitrary Waveform Generator Using Waveform Clipping Waveform Clipping Concepts Waveforms with high power peaks can cause intermodulation distortion, which generates spectral regrowth (a condition that interferes with signals in adjacent frequency bands). The clipping function allows you to reduce high power peaks. The clipping feature is available only with the Dual Arb mode.
Dual Arbitrary Waveform Generator Using Waveform Clipping As shown in Figure 5-12., simultaneous positive and negative peaks in the I and Q waveforms do not cancel each other, but combine to create an even greater peak.
Dual Arbitrary Waveform Generator Using Waveform Clipping 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 5-13). 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.
Dual Arbitrary Waveform Generator Using Waveform Clipping How Clipping Reduces Peak-to-Average Power You can reduce peak-to-average power, and consequently spectral regrowth, by clipping the waveform to a selected percentage of its peak power. The PSG vector signal generator provides two different methods of clipping: circular and rectangular. During circular clipping, clipping is applied to the combined I and Q waveform (|I + jQ|).
Dual Arbitrary Waveform Generator Using Waveform Clipping Figure 5-16 Chapter 5 Rectangular Clipping 117
Dual Arbitrary Waveform Generator Using Waveform Clipping Figure 5-17 118 Reduction of Peak-to-Average Power Chapter 5
6 Custom Arb Waveform Generator This chapter describes the Custom Arb Waveform Generator mode which is available only in E8267C PSG vector signal generators.
Custom Arb Waveform Generator Overview Overview Custom Arb Waveform Generator mode can produce a single modulated carrier or multiple modulated carriers. Each modulated carrier waveform must be calculated and generated before it can be output; this signal generation occurs on the internal baseband generator (Option 002/602). Once a waveform has been created, it can be stored and recalled which enables repeatable playback of test signals.
Custom Arb Waveform Generator Working with Predefined Setups (Modes) Working with Predefined Setups (Modes) When you select a predefined mode, default values for components of the setup (including the filter, symbol rate, and modulation type) are automatically specified. Selecting a Custom ARB Setup or a Custom Digital Modulation State 1. Preset the signal generator: press Preset. 2. Press Mode > Custom > Arb Waveform Generator > Setup Select. 3.
Custom Arb Waveform Generator Working with User-Defined Setups (Modes)-Custom Arb Only Working with User-Defined Setups (Modes)−Custom Arb Only Modifying a Single-Carrier NADC Setup In this procedure, you learn how to start with a single-carrier NADC digital modulation and modify it to a custom waveform with customized modulation type, symbol rate, and filtering. 1. Press Preset. 2. Press Mode > Custom > ARB Waveform Generator > Setup Select > NADC. 3.
Custom Arb Waveform Generator Working with User-Defined Setups (Modes)-Custom Arb Only Customizing a Multicarrier Setup In this procedure, you learn how to customize a predefined multicarrier digital modulation setup by creating a custom 3-carrier EDGE digital modulation state. 1. Press Preset. 2. Press Mode > Custom > Arb Waveform Generator > Multicarrier Off On. 3. Press Multicarrier Define > Initialize Table > Carrier Setup > EDGE > Done. 4. Highlight the Freq Offset value (500.
Custom Arb Waveform Generator Working with User-Defined Setups (Modes)-Custom Arb Only Recalling a User-Defined Custom Digital Modulation State In this procedure, you learn how to select (recall) a previously stored custom digital modulation state from the Memory Catalog (the Catalog of DMOD Files). 1. Press Preset. 2. Press Mode > Custom > ARB Waveform Generator > Setup Select. 3. Press More (1 of 2) > Custom Digital Mod State. 4.
Custom Arb Waveform Generator Working with Filters Working with Filters This section provides information on using predefined (page 126) and user-defined (page 127) FIR filters. NOTE The procedures in this section apply only to filters created in either the Custom Arb Waveform Generator or Custom Real Time I/Q Baseband mode; they do not work with downloaded files, such as those created in Matlab.
Custom Arb Waveform Generator Working with Filters • Filter Alpha enables you to adjust the filter alpha for a Nyquist or root Nyquist filter. If a Gaussian filter is used, you will see Filter BbT; this softkey is grayed out when any other filter is selected.
Custom Arb Waveform Generator Working with Filters Restoring Default FIR Filter Parameters 1. Preset the instrument: Press Preset. 2. Press Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Restore Default Filter. This replaces the current FIR filter with the default filter for the selected modulation format.
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. Press 1 > Enter.
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 6. Use the numeric keypad to type the first value (−0.000076) from the following table and press Enter. As you press the numeric keys, the numbers are displayed in the active entry area. (If you make a mistake, you can correct it using the backspace key.) Continue entering the coefficient values from the table until all 16 values have been entered. Coefficient Value Coefficient Value Coefficient Value 0 −0.000076 6 0.043940 12 0.123414 1 −0.
Custom Arb Waveform Generator Working with Filters real-time waveform generation, and 512 symbols for arbitrary waveform generation. The number of symbols equals the number of coefficients divided by the oversample ratio. 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.
Custom Arb Waveform Generator Working with Filters 132 Chapter 6
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).
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) QPSK and OQPSK (quadrature phase shift keying and offset quadrature phase shift keying) Includes: QPSK, IS95 QPSK, Gray Coded QPSK, OQPSK, IS95 OQPSK 2 90 bps − 100 Mbps 45 sps − 50 Msps 45 sps − 25 Msps BPSK (binary phase shift keying) 1 45 bps − 50 Mbps 45 sps − 50 Msps 45 sps − 50 Msps π/4 DQPSK 2 90 bps − 100 Mbps 45 sps − 50 Ms
Chapter 6 Modulation Type 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) QAM 4QAM 2 90 bps − 100 Mbps 45 sps − 50 Msps 45 sps − 25 Msps Quadrature Amplitude Modulation 16QAM 4 180 bps − 200 Mbps 45 sps − 50 Msps 45 sps − 12.5 Msps 32QAM 5 225 bps − 250 Mbps 45 sps − 50 Msps 45 sps − 10 Msps 64QAM 6 270 bps − 300 Mbps 45 sps − 50 Msps 45 sps − 8.
Custom Arb Waveform Generator Working with Modulation Types Working with Modulation Types The Modulation Type menu enables you to specify the type of modulation applied to the carrier signal when the Mod On Off hardkey is on. When the Custom Off On softkey is on: • For Custom Arb, the BBG creates a sampled version of the I/Q waveform based on a random data pattern and the modulation type that has been selected.
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 4. Press Return > Goto Row > 0011 0000 > Enter; this is row 48. 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 Creating a QPSK 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 4-symbol unbalanced QPSK modulation. 1. Press Preset. 2.
Custom Arb Waveform Generator Working with Modulation Types 6. Press More (1 of 2) > Load/Store > Store To File. If there is already a file name from the Catalog of IQ Files occupying the active entry area, press the following keys: Editing Keys > Clear Text 7. Enter a file name (for example, NEW4QAM) using the alpha keys and the numeric keypad. 8. Press Enter.
Custom Arb Waveform Generator Working with Modulation Types Creating an FSK Modulation Type User File with the Frequency Values Editor Use this procedure to set the frequency deviation for data 00, 01, 10, and 11 to configure a user-defined FSK modulation. 1. Press Preset. 2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User FSK > More (1 of 2) > Delete All Rows > Confirm Delete All Rows. This accesses the Frequency Values editor and clears the previous values. 3. Press 600 > Hz.
Custom Arb Waveform Generator Working with Modulation Types Modifying a Predefined FSK Modulation Type User File with the Frequency Values Editor Using the Frequency Values editor, you can define, modify, and store user-defined frequency shift keying modulation. The Frequency Values editor is available for custom Real-Time I/Q Baseband mode, but is not available for waveforms generated in custom Arb Waveform Generator mode. Use this example to learn how to add errors to a default FSK modulation. 1.
Custom Arb Waveform Generator Configuring Hardware Configuring Hardware • “To Set the ARB Reference” see page 144 To Set a Delayed, Positive Polarity, External Single Trigger Using this procedure, you learn how to utilize an external function generator to apply a delayed single-trigger to a custom multicarrier waveform. 1. Connect an Agilent 33120A function generator or equivalent to the signal generator PATT TRIGGER IN port, as shown in Figure 6-1. Figure 6-1 2. On the signal generator, press Preset.
Custom Arb Waveform Generator Configuring Hardware 11. On the signal generator, press Mode > Custom > Arb Waveform Generator > Digital Modulation Off On until On is highlighted. This generates a waveform with the custom multicarrier state and the display changes to Dig Mod Setup: Multicarrier. During waveform generation, the DIGMOD and I/Q annunciators activate and the new custom multicarrier state is stored in volatile ARB memory. The waveform should be modulating the RF carrier. 12. Press RF On/Off.
7 Custom Real Time I/Q Baseband This chapter describes the Custom Real Time I/Q Baseband mode which is available only in E8267C PSG vector signal generators.
Custom Real Time I/Q Baseband Overview Overview Custom Real Time I/Q Baseband mode can produce a single carrier, but it can be modulated with real time data that allows real time control over all of the parameters that affect the signal. The single carrier signal that is produced can be modified by applying various data patterns, filters, symbol rates, modulation types, and burst shapes.
Custom Real Time I/Q Baseband Working with Data Patterns Working with Data Patterns This section provides information on the following: • “Using a Predefined Data Pattern” on page 148 • “Using a User-Defined Data Pattern” on page 149 • “Using an Externally Supplied Data Pattern” on page 152 The Data menu enables you to select from predefined and user defined data patterns. Data Patterns are used for transmitting continuous streams of unframed data.
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 Using a User-Defined Data Pattern User Files (user-defined data pattern files) can be created and modified using the signal generator’s Bit File Editor or they can be created on a remote computer and moved to the signal generator for direct use; these remotely created data pattern files can also be modified with the Bit File Editor. For information on creating user-defined data files on a remote computer, see the programming guide.
Custom Real Time I/Q Baseband Working with Data Patterns 3. Enter the 32 bit values shown using the numeric keypad. Bit data is entered into the Bit File Editor in 1-bit format. The current hexadecimal value of the binary data is shown in the Hex Data column and the cursor position (in hexadecimal) is shown in the Position indicator. Enter These Bit Values Hexadecimal Data Cursor Position 4. Press More (1 of 2) > Rename > Editing Keys > Clear Text. 5.
Custom Real Time I/Q Baseband Working with Data Patterns Modifying an Existing Data Pattern User File In this example, you learn how to modify an existing data pattern user file by navigating to a particular bit position and changing its value. Next, you will learn how to invert the bit values of an existing data pattern user file.
Custom Real Time I/Q Baseband Working with Data Patterns Inverting the Bit Values of an Existing Data Pattern User File 1. Press 1011. This inverts the bit values that are positioned 4C through 4F. Notice that hex data in this row has now changed to 76DB6DB6, as shown in the following figure. Bits 4C through 4F inverted Hex Data changed 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.
Custom Real Time I/Q Baseband Working with Burst Shapes Working with Burst Shapes • “Configuring the Burst Rise and Fall Parameters” on page 154 • “Using User-Defined Burst Shape Curves” on page 155 The Burst Shape menu enables you to modify the rise and fall time, rise and fall delay, and the burst shape (either sine or user file defined).
Custom Real Time I/Q Baseband Working with Burst Shapes 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 Using User-Defined Burst Shape Curves You can adjust the shape of the rise time curve and the fall time curve using the Rise Shape and Fall Shape editors. Each editor enables you to enter up to 256 values, equidistant in time, to define the shape of the curve. The values are then resampled to create the cubic spline that passes through all of the sample points.
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 Working with Burst Shapes 7. Enter a file name (for example, NEWBURST) using the alpha keys and the numeric keypad. 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.
Custom Real Time I/Q Baseband Configuring Hardware Configuring Hardware • “To Set the BBG Reference” on page 158 • “To Set the External DATA CLOCK to Receive Input as Either Normal or Symbol” on page 159 • “To Set the BBG DATA CLOCK to External or Internal” on page 159 • “To Adjust the I/Q Scaling” on page 159 To Set the BBG Reference Setting for an External or Internal Reference 1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Configure Hardware.
Custom Real Time I/Q Baseband Configuring Hardware To Set the External DATA CLOCK to Receive Input as Either Normal or Symbol 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 external DATA CLOCK to receive input as either Normal or Symbol. 2. Press Ext Data Clock to select either Normal or Symbol; this setting has no effect in internal clock mode.
Custom Real Time I/Q Baseband Working with Phase Polarity Working with Phase Polarity To Set Phase Polarity to Normal or Inverted 1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Phase Polarity Normal Invert.
Custom Real Time I/Q Baseband Working with Differential Data Encoding symbols can be differentially encoded during the modulation process by assigning symbol table offset values associated with each data value. Figure 7-3 shows the 4QAM modulation in the I/Q Values editor. Figure 7-3 NOTE The number of bits per symbol can be expressed using the following formula. Because the equation is a ceiling function, if the value of x contains a fraction, x is rounded up to the next whole number.
Custom Real Time I/Q Baseband Working with Differential Data Encoding Differential Data Encoding In real-time I/Q baseband digital modulation waveforms, data (1’s and 0’s) are encoded, modulated onto a carrier frequency and subsequently transmitted to a receiver. In contrast to differential encoding, differential data encoding modifies the data stream prior to I/Q mapping.
Custom Real Time I/Q Baseband Working with Differential Data Encoding How Differential Encoding Works Differential encoding employs offsets in the symbol table to encode user-defined modulation schemes. The Differential State Map editor is used to introduce symbol table offset values, which in turn cause transitions through the I/Q State Map based on their associated data value.
Custom Real Time I/Q Baseband Working with Differential Data Encoding 1st 1st Symbol 3rd Symbol 5th { { Data = 0011100001 2nd Symbol 3rd { { { 2nd 5th Symbol 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 Using Differential Encoding Differential encoding is a digital-encoding technique that denotes a binary value by a signal change rather than a particular signal state. It is available for Custom Real Time I/Q Baseband mode. It is not available for waveforms generated by Arb Waveform Generator mode.
Custom Real Time I/Q Baseband Working with Differential Data Encoding Accessing the Differential State Map Editor • Press Configure Differential Encoding. This opens the Differential State Map editor. At this point, you see the data for the 1st symbol (00000000) and the cursor prepared to accept an offset value.You are now prepared to create a custom differential encoding for the user-defined default 4QAM I/Q modulation. Data Symbol Table Offset Values Entry Area Editing the Differential State Map 1.
Custom Real Time I/Q Baseband Working with Differential Data Encoding 4. Press 0 > Enter. This encodes the fourth symbol by adding a symbol table offset of 0. The symbol does not rotate through the state map when a data value of 11 is modulated. NOTE At this point, the modulation has two bits per symbol. For the data values 00000000, 00000001, 00000010, 00000011, the symbol values are 00, 01, 10, and 11 respectively. 5. Press Return > Differential Encoding Off On.
Custom Real Time I/Q Baseband Working with Differential Data Encoding 168 Chapter 7
8 Multitone Waveform Generator This chapter describes the Multitone mode, which is available only in E8267C PSG vector signal generators.
Multitone Waveform Generator Overview Overview The multitone mode builds a waveform that has up to 64 CW signals, or tones. Using the Multitone Setup table editor, you can define, modify, and store waveforms for playback. Multitone waveforms are generated by the internal I/Q baseband generator. The multitone waveform generator is typically used for testing the intermodulation distortion characteristics of multi-channel devices, such as mixers or amplifiers.
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 multitone signal should be available at the signal generator RF OUTPUT connector. Figure 8-2 on page 172 shows what the signal generator display should look like after all steps have been completed. Notice that the M-TONE, I/Q, RF ON, and MOD ON annunciators are displayed and the parameter settings for the signal are shown in the status area of the signal generator display.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms 7. Set the attenuation to 14 dB, so you’re not overdriving the input mixer on the spectrum analyzer. You should now see a waveform with nine tones and a 20 GHz center carrier frequency that is similar to the one shown in Figure 8-3 on page 173. You will also see IMD products at 1 MHz intervals above and below the highest and lowest tones.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms 6. Press Edit Item > -10 > dB. 7. Highlight the value (0) in the Phase column for the tone in row 4. 8. Press Edit Item > 123 > deg. 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.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms Figure 8-5 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 4. Press Q Offset and turn the rotary knob to further reduce the carrier feedthrough level. 5. Repeat steps 3 and 4 until you have reached the lowest possible carrier feedthrough level. 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 end tones. 9.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms To Determine Peak to Average Characteristics This procedure describes how to set the phases of the tones in a multitone waveform and determine the peak to average characteristics by plotting the complementary cumulative distribution function (CCDF). 1. Press Mode > Multitone > Initialize Table > Number of Tones > 64 > Enter. 2. Press Freq Spacing > 20 > kHz. 3. Press Initialize Phase Fixed Random to Fixed. 4. Press Done. 5.
Multitone Waveform Generator Creating, Viewing, and Optimizing Multitone Waveforms 10. Press Done. 11. Press Apply Multitone. 12. Press More (1 of 2) > Waveform Statistics > Plot CCDF. You should now see a display that is similar to the one shown in Figure 8-8. The CCDF plot displays the peak to average characteristics of the waveform with randomly generated phases and a random seed. The random phase setup simulates the typically random nature of multitone waveforms.
9 Two-Tone Waveform Generator In the following sections, this chapter describes the Two Tone mode, which is available only in E8267C PSG vector signal generators.
Two-Tone Waveform Generator Overview Overview The two-tone mode builds a waveform that has two equal-powered CW signals, or tones. The default waveform has two tones that are symmetrically spaced from the center carrier frequency, and have user-defined amplitude, carrier frequency, and frequency separation settings. The user can also align the tones left or right, relative to the carrier frequency.
Two-Tone Waveform Generator Creating, Viewing, and Modifying Two-Tone Waveforms Creating, Viewing, and Modifying Two-Tone Waveforms This section describes how to set up, generate, and modify a two-tone waveform while viewing it with a spectrum analyzer. Although you can view a generated two-tone signal using any spectrum analyzer that has sufficient frequency range, an Agilent Technologies PSA Series High-Performance Spectrum Analyzer was used for this demonstration.
Two-Tone Waveform Generator Creating, Viewing, and Modifying Two-Tone Waveforms Figure 9-2 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 9-3 Two-Tone Channels Carrier Feedthrough Intermodulation Distortion Carrier Feedthrough Distortion Chapter 9 183
Two-Tone Waveform Generator Creating, Viewing, and Modifying Two-Tone Waveforms 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. 1. On the spectrum analyzer, set the resolution bandwidth for a sweep rate of about 100-200 ms.
Two-Tone Waveform Generator Creating, Viewing, and Modifying Two-Tone Waveforms Figure 9-4 Main Marker Minimized Carrier Feedthrough Delta Marker Chapter 9 185
Two-Tone Waveform Generator Creating, Viewing, and Modifying Two-Tone Waveforms To Change the Alignment of a Two-Tone Waveform This procedure describes how to align a two-tone waveform left or right, relative to the center carrier frequency. Because the frequency of one of the tones is the same as the carrier frequency, this alignment eliminates carrier feedthrough. However, image frequency interference caused by left or right alignment may cause minor distortion of the two-tone signal.
10 Troubleshooting This chapter provides basic troubleshooting information for Agilent PSG signal generators. If you do not find a solution here, refer to the Service Guide. NOTE If the signal generator displays an error, always read the error message text by pressing Utility > Error Info.
Troubleshooting 188 Chapter 10
Troubleshooting RF Output Power Problems RF Output Power Problems Check the RF ON/OFF annunciator on the display. If it reads RF OFF, press RF On/Off to toggle the RF output on. RF Output Power too Low 1. Look for an OFFS or REF indicator in the AMPLITUDE area of the display. OFFS tells you that an amplitude offset has been set. An amplitude offset changes the value shown in the AMPLITUDE area of the display but does not affect the output power.
Troubleshooting RF Output Power Problems Signal Loss While Working with a Mixer If you experience signal loss at the signal generator’s RF output during low-amplitude coupled operation with a mixer, you can solve the problem by adding attenuation and increasing the RF output amplitude of the signal generator. Figure 10-1 on page 190 shows a hypothetical configuration in which the signal generator provides a low amplitude signal to a mixer.
Troubleshooting RF Output Power Problems Figure 10-2 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 Signal Loss While Working with a Spectrum Analyzer The effects of reverse power can cause problems with the signal generator’s RF output when the signal generator is used with a spectrum analyzer that does not have preselection capability. Some spectrum analyzers have as much as +5 dBm LO feedthrough at their RF input port at some frequencies.
Troubleshooting No Modulation at the RF Output There are three power search modes: manual, automatic, and span. When Power Search is set to Manual, pressing Do Power Search executes the power search calibration routine for the current RF frequency and amplitude. In this mode, if there is a change in RF frequency or amplitude, you will need to press Do Power Search again. When Power Search is set to Auto, the calibration routine is executed whenever the frequency or amplitude of the RF output is changed.
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 Sweep Problems Incorrect List Sweep Dwell Time If the signal generator does not dwell for the correct period of time at each sweep list point, follow these steps: 1. Press Sweep/List > Configure List Sweep. This displays the sweep list values. 2. Check the sweep list dwell values for accuracy. 3. Edit the dwell values if they are incorrect.
Troubleshooting Data Storage Problems Data Storage Problems Registers With Previously Stored Instrument States are Empty The save/recall registers are backed-up by a battery when line power to the signal generator is not connected. The battery may need to be replaced. To verify that the battery has failed: 1. Turn off line power to the signal generator. 2. Unplug the signal generator from line power. 3. Plug in the signal generator. 4. Turn on the signal generator. 5.
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 Signal Generator Locks Up Signal Generator Locks Up If the signal generator is locked up, check the following: • Make sure that the signal generator is not in remote mode (in remote mode, the R annunciator appears on the display). To exit remote mode and unlock the front panel keypad, press Local. • Make sure that the signal generator is not in local lockout condition. Local lockout prevents front panel operation. For more information on local lockout, refer to the Programming Guide.
Troubleshooting Signal Generator Locks Up 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: 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/DCΦM calibration. Refer to the DCFM/DCΦM Cal softkey description in the Key Reference. c.
Troubleshooting Error Messages Error Messages If an error condition occurs in the signal generator, it is reported to both the front panel display error queue and the SCPI (remote interface) error queue. These two queues are viewed and managed separately; for information on the SCPI error queue, refer to the Programming Guide. NOTE When there is an unviewed message in the front panel error queue, the ERR annunciator appears on the signal generator’s display.
Troubleshooting Error Messages Error Message Format When accessing error messages through the front panel display error queue, the error numbers, messages and descriptions are displayed on an enumerated (“1 of N”) basis. Error messages appear in the lower-left corner of the display as they occur.
Troubleshooting Error Messages Error Message Types Events do not generate more than one type of error. For example, an event that generates a query error will not generate a device-specific, execution, or command error. Query Errors (–499 to –400) indicate that the instrument’s output queue control has detected a problem with the message exchange protocol described in IEEE 488.2, Chapter 6. Errors in this class set the query error bit (bit 2) in the event status register (IEEE 488.2, section 11.5.1).
Troubleshooting Returning a Signal Generator to Agilent Technologies Returning a Signal Generator to Agilent Technologies To return your signal generator to Agilent Technologies, follow these steps: 1. Be prepared to give your service representative as much information as possible regarding the signal generator’s problem. 2. Call the phone number listed in Table 10-1 appropriate to the signal generator’s location.
Troubleshooting Returning a Signal Generator to Agilent Technologies 204 Chapter 10
Index Symbols ΦM, 81 Numerics 10 MHz connectors, 24 128QAM I/Q modulation, creating, 137 1410, application note, 170, 180 A AC power receptacle, 18 ACP, 126, 154 active entry area (display), 13 adjustments, display, 11 Agilent Technologies, 203 ALC annunciator, 14 bandwidth selection, 59 input connector, 9 limitations, amplitude, 61 off mode, setting, 192 with attenuator option, 63 Alpha adjustment (filter), 126 alternate ramp sweep, 43 AM, 14, 79 amplifier, microwave, 47 amplitude display area, 16 hardkey,
Index continuous list sweep, 36 step sweep, 33 wave RF output, 28 contrast adjustments (display), 11 correction array (user flatness) configuration, 66 load from step array, 66 viewing, 67 See also user flatness correction couplers/splitters, using, 60 Custom Arb waveform generator, 119–144 Custom Real Time I/Q baseband, 145–167 CW PSG features, 2 D data, 196 clock, 12, 159 fields, editing, 27 files, 52 input, 12 patterns, 147 See also instrument state register See also memory catalog default FIR filter, re
Index front panel description, 6–16 FSK files, 52 modulation, 136, 141, 142 G GATE/PULSE/TRIGGER INPUT connector, 10 Gaussian filter, selecting, 126 Goto Row softkey, 27 GPIB, 18, 69 H hardkeys, 6–11 hardware, configuring, 143, 158 header files (ARB waveform), 88–98 Help hardkey, 8 help mode troubleshooting, 197 Hold hardkey, 11 I I OUT connector, 22 I/O connector, auxiliary, 21 I/Q 4QAM state map, 161 annunciator, 14 files, 52 input connectors, 12 modulation, 140, 165 scaling, adjusting, 159 I-bar OUT conn
Index microwave amplifier, 47 mixer, signal loss while using, 190 mm-wave source module extending frequency range with, 47 leveling with, 63 user flatness correction array, creating, 69–75 mod on/off, 9, 15 models, signal generator, 2 modes of operation, 5 modulation amplitude. See AM analog, 78 annunciators, 14–16 applying, 50 file catalogs, 52 frequency. See FM on/off hardkey, 9 phase.
Index rectangular clipping, 112 reference amplitude, setting, 30 frequency, setting, 29 oscillator bandwidth, adjusting, 76 registers, 54, 55 remote control, 69 remote operation annunciator, 15 repair, return instructions, 203 Return hardkey, 11 RF output annunciator, 15 configuring, 28–49 connector, 10 leveling, external, 60–63 mm-wave source module, using, 47 On/Off hardkey, 9 sweeping, 31 troubleshooting, 189 user flatness correction, 64–75 rise delay, burst shape, 154 rise time, burst shape, 154 root Ny
Index user-defined burst shape curves, 155 data patterns, 149 files, 52 filters, 127, 129 modulation type custom arb, 122 real time I/Q, 137, 165 V vector PSG features, 4 VIDEO OUT connector, 10 W waveforms analog modulation, 78 ARB header files, 88–98 clipping, 112–118 custom, 119–144 Custom Real Time I/Q baseband, 145–167 dual arb, 87–118 file catalogs, 52 file, renaming, 103 markers, 104 multitone, 169–178 player, dual ARB, 99 segments, 100–103 sequence blanking markers, 110 building and storing, 101–103
