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Keysight EXG and MXG X-Series Signal Generators User’s Guide
Troubleshooting
RF Output
Signal Loss While Working with a Spectrum Analyzer
The effects of reverse power can cause problems with the RF output when you use the signal
generator with a spectrum analyzer that does not have preselection. Use an unleveled operating
mode (described on
).
A spectrum analyzer can have as much as +5 dBm LO feedthrough at its RF input port at some
frequencies. If the frequency difference between the LO feedthrough and the RF carrier is less than
the ALC bandwidth, the LO’s reverse power can amplitude modulate the signal generator’s RF
output. The rate of the undesired AM equals the difference in frequency between the spectrum
analyzer’s LO feedthrough and the signal generator’s RF carrier.
Reverse power problems can be solved by using one of the unleveled operating modes.
See:
—
and
—
“Power Search Mode” on page 103
To avoid damaging or degrading the performance of the signal generator,
do not exceed 33 dBm (2W)
maximum
of reverse power levels at the RF
input. See also
Tips for Preventing Signal Generator Damage
on
www.keysight.com
.
