Agilent Technologies 83236B, Operating Manual, Page: 71 / 164

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Chapter 3, Programming the PCS Interface using GPIB Control
Overview of Programming Issues
Analyzer
Attenuator Setting
The PCS Interface’s analyzer path has a 0 to 40 dB attenuator with 1 dB steps.
This attenuator is adjusted to optimize the signal level through the PCS
Interface’s downconverter to the Test Set’s ANT IN port.
After the UUT’s transmitter signal is applied to the PCS Interface’s RF IN/OUT
port, the setting of the analyzer path attenuator can be automatically set using an
GPIB command. When the command is received, the PCS Interface uses the
internal peak detector to measure the peak power at its RF IN/OUT port, then
computes and sets the analyzer path attenuator accordingly.
NOTE: This is a one-time setting and does not place the PCS Interface in an auto-ranging mode. If
the TX signal level changes, the attenuation setting command should be sent again.
The automatic computation performed by the PCS Interface’s CPU to set the
attenuator uses a factor stored in the PCS Interface; the attenuation step accuracy
factor. The attenuator step accuracy correction factor is established as part of the
factory calibration. This factor is also a function of the current analyzer
frequency, therefore the automatic attenuator setting should be done after the
UUT’s transmitter frequency is set in the PCS Interface and after the UUT’s
transmitter signal is applied to the RF IN/OUT port.
NOTE: The analyzer path attenuator can also be set to a specified value over GPIB.