Keysight M9421A - Page 951

3 WLAN Mode
3.6 Modulation Analysis Measurement
See "RF Center Freq " on page 953 and "Ext Mix Center Freq " on page 954 and "I/Q Center Freq " on
page 955
State Saved Saved in instrument state
Min Depends on instrument maximum frequency, mode, measurement, and selected input..
See "RF Center Freq " on page 953 and "I/Q Center Freq " on page 955
Max Depends on instrument maximum frequency, mode, measurement, and selected input..
See "RF Center Freq " on page 953 and "I/Q Center Freq " on page 955
More Information
In measurements that also have Start Freq and Stop Freq controls, pressing Center
Freq sets the frequency entry mode to Center/Span. In Center/Span mode, the
center frequency and span values are displayed below the graticule, and the default
active function in the Frequency menu is Center Freq. In the Start/Stop annotation
mode, Start Freq and Stop Freq are displayed below the graticule instead of Center
Freq and Span.
Pressing Center Freq also sets the frequency entry mode to Center/Span. In
Center/Span mode, the center frequency and span values are displayed below the
graticule, and the default active function in the Frequency menu is Center Freq.
When frequency Scale Type is set to log, pressing Center Freq sets the frequency
that corresponds to the arithmetic mean of the start frequency and stop frequency,
which is not at the horizontal center of the graticule.
The center frequency setting is the same for all measurements within a mode, that
is, it is Meas Global. Some modes are also able to share a Mode Global center
frequency value. If this is the case, the Mode will have a Global tab in its Meas Setup
menu.
The Center Freq function sets (and queries) the Center Frequency for the currently
selected input. If your analyzer has multiple inputs, and you select another input, the
Center Freq changes to the value for that input. SCPI commands are available to
directly set the Center Freq for a specific input.
Center Freq is remembered as you go from input to input. Thus you can set a Center
Freq of 10 GHz with the RF Input selected, change to BBIQ and set a Center Freq of
20 MHz, then switch to External Mixing and set a Center Freq of 60 GHz, and when
you go back to the RF Input the Center Freq will go back to 10 GHz; back to BBIQ
and it is 20 MHz; back to External Mixing and it is 60 GHz.
Center Frequency Presets
The following table provides the Center Frequency Presets for the Spectrum
Analyzer mode, and the Max Freq, for the various frequency options:
951 WLAN Mode User's &Programmer's Reference