Atek HP 8753D, User Manual, Page: 364 / 677

P ower Loss Correction List
If a directional coupler or power splitter is used to sample the RF power output of the analyzer ,
the RF signal going to the power meter may be dierent than that going to the test device . A
directional coupler will attenuate the RF signal by its specied coupling factor . The dierence
in attenuation between the through arm and the coupled arm (coupling factor) must be entered
using the loss/sensor list menu. Non-linearities in either the directional coupler or power
splitter can be corrected in the same way .
P ower loss information is entered in much the same way as limit line parameters . Up to 12
segments may be entered, each with a dierent attenuation value . The entered data will not
be lost if the instrument's power is cycled.
P ower Sensor Calibration F actor List
Two power sensor calibration data lists can be created in the analyzer . No single power sensor
covers the entire frequency range of the analyzer , therefore the calibration data for two
dierent power sensors must be available . The entered data will not be lost if the instrument's
power is cycled.
Speed and A ccuracy
The speed and accuracy of a power meter calibration vary depending on the test setup and the
measurement parameters . F or example , number of points , number of readings , if the power is
less than 020 dBm, continuous versus sample and sweep mode . A ccuracy is improved if you
set the source power such that it is approximately correct at the measurement port. P ower
meter calibration should then be turned on. With number of readings = 2, very accurate
measurements are achieved.
T able 6-6 shows typical sweep speed and power accuracy . The times given apply only to the
test setup for continuous correction or for the rst sweep of sample-and-sweep correction.
The typical values given in T able 6-6 were derived under the following conditions:
T est Equipment Used
HP 8753D network analyzer
HP 436A power meter
HP 8485A power sensor
Stimulus P arameters
The time required to perform a power meter calibration depends on the source power and
number of points tested. The parameters used to derive the typical values in T able 6-6 are as
follows:
number of points: 51, 100 kHz to 3 GHz
test port power: equal to calibration power
Sweep time is linearly proportional to the number of points measured. F or example , a sweep
taking 49 seconds at 51 points will take approximately 98 seconds if 101 points are measured.
6-98 Application and Operation Concepts