3 VMA Mode
3.7 Power Stat CCDF Measurement
Ext Mix Center Freq
Specifies the External Mixer Center Frequency. Sets the Center Frequency to use
when the External Mixer is selected, even if the External Mixer input is not the input
that is selected at the time the command is sent. Note that Center Frequency in the
Frequency menu on the front panel always applies to the currently selected input.
Remote
Command
[:SENSe]:FREQuency:EMIXer:CENTer <freq>
[:SENSe]:FREQuency:EMIXer:CENTer?
Example
:FREQ:EMIX:CENT 60 GHz
:FREQ:EMIX:CENT?
Notes This command is the same in all Modes, but the parameter is Measurement Global, so the value is
independent in each Mode and common across all the measurements in the Mode
Couplings When returning to External Mixing after having switched to one of the other inputs (for example, RF),
you will come back into the settings that you had when you left External Mixing. So, you will come back
to the band you were in with the Center Frequency that you had. However, Span is not an input-
dependent parameter, therefore you will bring the span over from the other input. Therefore, the
instrument comes back with the span from the previous input, limited as necessary by the current mixer
setup
Preset When a Mode Preset is performed while in External Mixing, the Start frequency of the current Mode is
set to the nominal Min Freq of the lowest harmonic range in the Harmonic Table for the current mixer
setup. Similarly, the Stop frequency of the current Mode is set to the nominal Max Freq of the highest
harmonic range in the Harmonic Table. The Center Freq thus presets to the point arithmetically
equidistant from these two frequencies
Note that, if the current measurement has a limited Span available to it, and cannot achieve the Span
shown in the table (Span=Stop Freq – Start Freq), the instrument uses the maximum Span the
measurement allows, and still sets the Center Freq to the midpoint of the Start and Stop Freq values in
the Harmonic Table
When Restore Input/Output Defaults is performed, the mixer presets to the 11970A, whose Start and
Stop frequencies are 26.5 and 40GHz respectively. The center of these two frequencies is 33.25GHz
Therefore, after Restore Input/Output Defaults, if you go to External Mixing and do a Mode Preset while
in Spectrum Analyzer Mode, the resulting Center Freq is 33.25GHz
State Saved Yes
Min The minimum frequency in the currently selected mixer band + 5 Hz
Max The maximum frequency in the currently selected mixer band - 5 Hz
I/Q Center Freq
Specifies the I/Q Center Frequency. Sets the Center Frequency to be used when the
I/Q input is selected, even if the I/Q input is not the input that is selected at the time
the command is sent. Note that Center Frequency in the Frequency menu on the
front panel always applies to the currently selected input.
Remote
Command
[:SENSe]:FREQuency:IQ:CENTer <freq>
1133 Vector Modulation Analyzer Mode User's &Programmer's Reference