R&S SMA100B, User Manual

Page: 182 / 581

Improving Level Performance
R&S
®
SMA100B
167 User Manual 1178.3834.02 ─ 03
"User" The filter length is defined manually, with the parameter Filter Length .
As the filter length works as a multiplier for the time window, constant
filter length results in a constant measurement time.
Values 1 and 2N are allowed.
"Fixed Noise" The averaging factor is selected so that the sensor's intrinsic noise (2
standard deviations) does not exceed the specified noise content.
Set the noise content value with the parameter
Noise/Signal Ratio .
To avoid long settling times when the power is low, limit the averag-
ing factor with the parameter
Timeout .
Remote command:
:SENSe<ch>[:POWer]:FILTer:TYPE
on page 360
Filter Length ← Sensor settings
Sets or indicates the filter length, depending on the selected filter mode.
●
"Filter > Auto" indicates the used filter length.
●
"Filter > User" enables you to adjust a manual optimal filter length.
●
"Filter > Fixed Noise" the filter length is blanked.
Remote command:
:SENSe<ch>[:POWer]:FILTer:LENGth:AUTO?
on page 358
:SENSe<ch>[:POWer]:FILTer:LENGth[:USER]
on page 359
Noise/Signal Ratio ← Sensor settings
For "Filter > Fixed Noise", sets the noise content.
Remote command:
:SENSe<ch>[:POWer]:FILTer:NSRatio
on page 359
Auto Once ← Sensor settings
Searches the optimum filter length for the current measurement conditions. The result
is indicated with the parameter
Filter Length .
See also "About the measuring principle, averaging filter, filter length, and achieving
stable results" on page 161.
Remote command:
:SENSe<ch>[:POWer]:FILTer:SONCe
on page 360
Timeout ← Sensor settings
For "Filter > Fixed Noise", sets a time limit for the averaging process.
Remote command:
:SENSe<ch>[:POWer]:FILTer:NSRatio:MTIMe
on page 360
Default Aperture Time ← Sensor settings
The sensor default setting is sufficient. Disable this parameter to specify a user-defined
aperture time per sensor, if, for example, the readings vary.
To obtain stable readings, set the Aperture Time exactly to one modulation period.
Remote command:
:SENSe<ch>[:POWer]:APERture:DEFault:STATe
on page 357
Using Power Sensors