Rohde & Schwarz R&S FSP Series, Operating Manual

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R&S FSP Remote Control – Programming Examples
More Complex Programming Examples
7.22 Operating Manual 1164.4556.12 - 06
7.3.7 Fast Level Measurement Using Frequency Lists
A typical task for the R&S FSP is power measurement at a number of frequency
points, e.g. at multiples of the fundamental (harmonics measurement), or at frequen-
cies defined by a mobile radio standard (e.g. spectrum due to transients at
± 200 kHz, ± 400 kHz, etc. about the carrier frequency of a GSM signal). In many
cases, different level and/or bandwidth settings are required for the different fre-
quency points to match the channel spacing and meet the requirements of dynamic
range.
Especially for this application, the R&S FSP offers a number of remote-control func-
tions (commands available in SENSe:LIST subsystem) that allow level measure-
ment based on a frequency list with different instrument settings assigned to
different frequencies. Not only the frequency list can be programmed, but also the
measurement types (PEAK, RMS, AVG) to be performed simultaneously can be
selected.
The example below describes a harmonics measurement on a dual-band amplifier.
The harmonics level in general decreases as the frequency increases. To boost
measurement sensitivity, therefore, the reference level is lowered by 10 dB from the
third harmonic.
The following settings are used:
• Reference level: 10.00 dBm up to 2nd harmonic, 0 dBm from 3rd harmonic
• RF attenuation: 20 dB
• Electronic attenuation: 0 dB
• RBW: 1 MHz
• VBW: 3 MHz
• Filter type: NORMal
• Measurement time: 300
µ
s
• Trigger delay: 100
µ
s
• Trigger: video, 45%
The frequencies are selected in ascending order to minimize system-inherent wait-
ing times resulting from frequency changes.
At each frequency point the peak power and the rms power are measured. The peak
power and the rms power values are stored alternately in the results memory.
Frequency Type
935.2 MHz GSM 900 fundamental
1805.2 MHz GSM 1800 fundamental
1870.4 MHz GSM 900 2nd harmonic
2805.6 MHz GSM 900 3rd harmonic
3610.4 MHz GSM 1800 2nd harmonic
3740.8 MHz GSM 900 4th harmonic
5815.6 MHz GSM 1800 3rd Harmonic