Keysight x-series User Manual

3 Spectrum Analyzer Mode
3.4 Occupied BW Measurement
3.4.6.1 Settings
Contains controls that pertain to the X-Axis parameters of the measurement. These
parameters control how data on the vertical (X) axis is displayed and control
instrument settings that affect the horizontal axis.
Center Frequency
Sets the frequency that corresponds to the horizontal center of the graticule (when
frequency Scale Type is set to linear). While adjusting Center Frequency, Span is
held constant, which means that both Start Freq and Stop Freq will change.
In measurements that also have Start Freq and Stop Freq controls, pressing Center
Frequency 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 Frequency. In the
Start/Stop annotation mode, Start Freq and Stop Freq are displayed below the
graticule instead of Center Frequency and Span.
Pressing Center Frequency 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
Frequency.
When Display Scale Type is set to LOG, pressing Center Frequency 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 has a Global tab in its Meas Setup
menu.
Center Frequency sets (and queries) the center frequency for the currently selected
input. If your instrument has multiple inputs, and you select another input, Center
Frequency changes to the value for that input. SCPI commands are available to
directly set Center Frequency for a specific input (see "RF Center Frequency" on
page 786 and "Ext Mix Center Freq" on page 787).
Center Frequency is remembered as you go from input to input. Thus you can set a
Center Frequency of 10GHz with the RF Input selected, change to BBIQ and set a
Center Frequency of 20MHz, then switch to External Mixing and set a Center
Frequency of 60GHz. When you return to the RF Input, Center Frequency reverts to
10GHz; back to BBIQ and it is 20MHz; back to External Mixing and it is 60GHz.
Remote Command
[:SENSe]:FREQuency:CENTer <freq>
[:SENSe]:FREQuency:CENTer?
Spectrum Analyzer Mode User's &Programmer's Reference 783

Keysight x-series Specifications

General

Analysis Bandwidth	Up to 1 GHz (depending on model)
Real-Time Bandwidth	Up to 1 GHz (depending on model)
Form Factor	Benchtop
Connectivity	LAN, USB, GPIB
Resolution Bandwidth	1 Hz to 10 MHz (depending on model)