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Remote control commands
R&S
®
NRPxxP
56
User Manual 1179.5760.02 ─ 02
For information on querying the measurement results, see
8.6.1.1
Defining the sampling window
SENSe<Sensor>:[POWer:][AVG:]APERture
<integration_time>
Sets the duration of the sampling window. During this time interval, the average signal
power is measured.
Parameters:
<integration_time>
Range:
1.0e-6 to 1.0
*RST:
10.0e-6
Default unit: Seconds
8.6.1.2
Reducing noise and zero offset
The smoothing filter can reduce result fluctuations caused by modulation. But activat-
ing it increases the inherent noise of the power sensor by approx. 20
%, so do not acti-
vate if it unless required.
SENSe<Sensor>:[POWer:][AVG:]SMOothing:STATe
<state>
Enables or disables the smoothing filter, a steep-edge digital lowpass filter. If you can-
not adjust the aperture time exactly to the modulation period, the filter reduces result
fluctuations caused by modulation.
Parameters:
<state>
ON | OFF
*RST:
OFF
Example:
SMO:STAT OFF
8.6.1.3
Measuring modulated signals
When measuring modulated signals in continuous average mode, the measurement
can show fluctuation due to the modulation. If that is the case, adapt the size of the
sampling window exactly to the modulation period to get an optimally stable display. If
the modulation period varies or is not precisely known, you can also activate the
smoothing function.
With smoothing activated, the selected sampling window has to be 5 to 9 times larger
than the modulation period so that the fluctuations caused by modulation are suffi-
ciently reduced. The sampling values are subjected to weighting (raised-von-Hann win-
dow), which corresponds to video filtering.
If you deactivate the smoothing filter, 300 to 3000 periods are required to obtain the
same effect. The sampling values are considered equivalent and are averaged in a
sampling window, which yields an integrating behavior of the measuring instrument. To
obtain optimum suppression of variations in the result, exactly adapt the modulation
Configuring the measurement modes