Keysight Technologies X Series Service Manual page 232

RF Section Troubleshooting (Millimeter-Wave Analyzers)
Troubleshooting
High Band Preamp (Option P07, P13, P26, P32, P44)
If a preamp option listed above is installed, the High Band preamp can be
verified as follows:
View the 4.8 GHz calibrator signal on screen. Press AMPTD, More, Internal
Preamp, Full Range to activate the preamp.The expected operation is the
signal level will not change more than +/- 0.5 dB and the noise floor will
increase due to the fact the input attenuation was automatically increased.
If the amplitude error when switching the preamp on and off is greater than 0.5
dB, assure that any other internal alignment failures are resolved since the
System Gain alignment must run before optimum performance is possible. The
amplitude error could be caused by poor frequency response, and performing
the high band frequency response adjustment (using the calibration software)
will adjust the preamp on, high band path. Assure you have evaluated all
causes including A15 Front End Controller switching problems, before you
replace the Front End assembly.
High Band Mixing Equations
For input signal frequencies from 3.6 GHz to 8.4 GHz:
RF = LO x N − IF
IF = LO x N − RF
LO x N = IF + RF
For input signal frequencies above 8.4 GHz to 44 GHz:
RF = LO x 2 x N − IF
IF = LO x 2 x N − RF
LO x 2 x N = RF + IF
Microwave Preselector Bypass (Option MPB)
Allows the YTF to be bypassed improving amplitude accuracy.
Assure start frequency is 3.6 GHz or greater. Press Amplitude, uW Path
Control, uW Preselector Bypass. When the bypass switch, Switch 4, changes
state you will hear a click. Depending on the signal source connected, you may
see many "signals" appear on screen because without preselection, the
analyzer will display images and multiples. The real input signal should not
change amplitude when you switch the uW Preselector Bypass on and off.
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where RF is the input signal at the signal analyzer
where N is the harmonic mixing mode:
N = 1 for 3.5 GHz to 8.4 GHz
where RF is the input signal at the signal analyzer
where N is the harmonic mixing mode:
N = 1 for 8.4 GHz to 17.1 GHz
N = 2 for 17.1 GHz to 34.0 GHz
N = 4 for 34.0 GHz to 44 GHz
Keysight N9010A EXA Service Guide