Agilent Technologies 11970-90031 Identify signals with the frequency-shift method

34 Chapter 2
Operation
Using the Mixers with the 856X Series Spectrum Analyzers
Operation
Figure 2-11 Signal Responses Produced by a 50 GHz Signal in U Band
Identify signals with the frequency-shift method
6. Signal-identification routines that identify the signal and images are available on
instruments with firmware revisions ≤920528, or with Option 008. The frequency-shift
method of identifying valid signals uses the spectrum-analyzer function SIG ID ON OFF.
When using this function, smaller spans will yield more accurate measurements.
a. Span down to 50 MHz.
b. Press AUX CTRL, EXTERNAL MIXER, SIGNAL IDENT.
c. Press SIG ID ON OFF until ON is selected.
Any signal not produced by the currently selected harmonic will be shifted horizontally
on alternate sweeps (see Figure 2-12). Therefore, when viewing the display, on alternate
sweeps the signal will appear, then not appear, at the frequency of interest. The correct
signal produced by the selected harmonic will be shifted in a vertical direction only, as
shown in Figure 2-13.