Keysight E6680A - Span

3 IQ Analyzer (Basic) Mode
3.1 Complex Spectrum Measurement
highest harmonic range in the Harmonic Table. Center Frequency thus presets to the point arithmet-
ically 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 that the
measurement allows, and still sets Center Frequency to the midpoint of the Start Freq 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 40GHz respectively. The center of these two frequencies is 33.25 GHz
Therefore, after Restore Input/Output Defaults, if you switch to External Mixing and do a Mode Preset
while in the Spectrum Analyzer Mode, the resulting Center Frequency is 33.25GHz
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
If the knob or step keys are being used, also depends on the value of the other three interdependent
parameters Span, Start Freq and Stop Freq
Span
Lets you modify the frequency span in the spectrum view for the complex spectrum
measurement. While adjusting Span, Center Frequency is held constant and the
displayed frequency range changes symmetrically about Center Frequency.
Span is translated to the required Digital IF bandwidth for the FFT analysis. The
instrument’s Digital IF bandwidth is always equal to or greater than this value. The
maximum Span depends on the instrument type and the options that are installed.
The maximum Span is equal to the maximum bandwidths of the IF Paths.
If Span is set to a value greater than the maximum allowable span of the instrument,
an error message is generated indicating the data is out of range and was clipped to
upper limit.
Remote Command Complex Spectrum:
[:SENSe]:SPECtrum:FREQuency:SPAN <freq>
[:SENSe]:SPECtrum:FREQuency:SPAN?
Streaming:
[:SENSe]:STReaming:FREQuency:SPAN <freq>
[:SENSe]:STReaming:FREQuency:SPAN?
Example
:SPEC:FREQ:SPAN 10
:SPEC:FREQ:SPAN?
Dependencies To set a 2 GHz Span with Option R20, Center Frequency must be greater than or equal to 3.5GHz
To set a 4 GHz Span with Option R40, Center Frequency must be greater than or equal to 10GHz
Couplings Changing Span causes "Res BW" on page 186 and Digital IF BW to change automatically, and affects
201 IQ Analyzer Mode User's &Programmer's Reference