Keysight x-series Programmer's Reference

3 VMA Mode
3.1 Digital Demod Measurement
Optimize EVM
This is an "immediate action" function to optimize EVM for the current input signal. It
is used to set the combination of the preamp, mechanical and electronic
attenuation, and IF gain value based on the measured signal peak level. Its purpose
is to get better EVM results by improving the SNR and avoid ADC overload at the
same time.
After this control is pressed, Pre-Adjust for Min Clipping@50227 changes to Off and
"IF Gain" on page 362 Auto changes to Manual.
NOTE
Before selecting this function, the "EVM Optimization Method" on page 303
should be selected.
Remote Command
[:SENSe]:DDEMod:OPTimize
Example
:DDEM:OPT
Dependencies Does not appear in VXT Models M9410A/11A/15A/16A/20A
EVM Optimization Method
There are 2 methods for EVM Optimization:
NORMal
Captures input signal, measures its peak power, then the algorithm will find
proper setting combination for attenuation, preamp and IF Gain
ITERative
Captures input signal multiple times in a iteration process, demodulates the signal
and calculates EVM for each iteration, then finds setting combination for
attenuation, preamp and IF Gain with minimum EVM
The Iterative method is slower than the Normal method but it can always get better
EVM.
Remote Command
[:SENSe]:DDEMod:OPTMethod NORMal | ITERative
[:SENSe]:DDEMod:OPTMethod?
Example
:DDEM:OPTM NORM
:DDEM:OPTM?
Dependencies Does not appear in VXT Models M9410A/11A/15A/16A/20A
Couplings Disabled when Segment Number is greater than one
Preset
NORMal
State Saved Saved in instrument state
Range Normal | Iterative
303 Vector Modulation Analyzer Mode User's &Programmer's Reference

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)