Specifications

The power flatness calibration feature of the 8510C
network analyzer provides a more precise power
level to the AUT. A 437B or 438A power meter and
an appropriate power sensor such as the
Agilent 8481A, 8485A or 8487A are required.
The power sensor is attached to the desired test
port, after any cables or adapters leading up to the
point where the AUT will be connected, and a sin-
gle power calibration sweep is performed. The
power meter monitors the test port power at each
measurement point across the frequency band of
interest, and a table of power corrections versus
frequency is derived and stored in the 8360 syn-
thesized sweeper. When the power meter is discon-
nected and the test port flatness correction is
enabled, the source will adjust the output power to
compensate for path losses at each measurement
point in the frequency span, with no degradation
in measurement speed.
1. Configure the system as shown in Figure 10.
Connect the 437B power meter to the system bus
of the 8510C. Zero and calibrate the power meter.
Verify that the address of the power meter matches
the setting in the network analyzer. The default
address for the 437B is 13.
[LOCAL] {POWERMETER} [13] [x1]
2. Choose the appropriate measurement parame-
ters. Set the source to maximum leveled power
(P1) at the highest frequency in the measurement
span. See Appendix C, “8360 Series Synthesized
Sweepers maximum leveled power.”
[START] [2] [G/n]
[STOP] [26.5] [G/n]
[S21]
STIMULUS [MENU]
{POWER MENU}
{POWER SOURCE 1}P1 [x1]
3. When the flatness calibration is initiated, the
analyzer sends the source a list of flatness correc-
tion frequencies equal to the number of trace
points set on the analyzer. If needed, adjust the
number of analyzer trace points.
STIMULUS [MENU]
{NUMBER of POINTS}
4. Connect the power sensor to the active test port
(normally port 1 where the input of the AUT is
connected).
5. Initiate the flatness calibration.
STIMULUS [MENU]
{POWER MENU}
{POWER FLATNESS}
{CALIBRATE FLATNESS}
{FLATNESS CAL START}
11
Power flatness correction
Figure 9. Power flatness correction setup
AUT
Attenuator
(if needed)
8510 System Bus
437B
Power Meter
8485A
Power sensor