Rohde & Schwarz R&S FSP Series, Operating Manual

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R&S FSP Getting Started
Noise Measurements
2.22 Operating Manual 1164.4556.12 - 06
2.4.3 Measuring Phase Noise
The R&S FSP has an easy-to-use marker function for phase noise measurements.
This marker function indicates the phase noise of an RF oscillator at any carrier in
dBc in a bandwidth of 1 Hz.
2.4.3.1 Measurement Example – Measuring the phase noise of a signal generator at a
carrier offset of 10 kHz
Test setup:
Settings on the signal generator (e.g. R&S SMIQ):
Measurement using R&S FSP:
1. Set the R&S FSP to its default state
➢
Press the PRESET key.
R&S FSP is in its default state.
2. Set the center frequency to 100 MHz and the span to 50 kHz
➢
Press the FREQ key and enter 100 MHz .
➢
Press the SPAN key and enter 50 kHz .
3. Set the R&S FSP’s reference level to 0 dBm (=signal generator level)
➢
Press the AMPT key and enter 0 dBm .
4. Enable phase noise measurement
➢
Press the MKR FCTN key.
➢
Press the PHASE NOISE ! softkey.
The R&S FSP activates phase noise measurement. Marker 1 (=main marker)
and marker 2 (= delta marker) are positioned on the signal maximum. The
position of the marker is the reference (level and frequency) for the phase
noise measurement. A horizontal line represents the level of the reference
point and a vertical line the frequency of the reference point. Data entry for the
delta marker is activated so that the frequency offset at which the phase noise
is to be measured can be entered directly.
5. 10 kHz frequency offset for determining phase noise.
➢
Enter 10 kHz .
The R&S FSP displays the phase noise at a frequency offset of 10 kHz. The
magnitude of the phase noise in dBc/Hz is displayed in the delta marker output
field at the top right of the screen (delta 2 [T1 PHN]).
Frequency: 100 MHz
Level: 0 dBm
Signal
generator
FSP