Rohde & Schwarz R&S FSH - Page 32

Performance Test R&S FSH
1145.5973.82 1.8 E-11
Checking the phase noise
Test equipment: Signal generator (refer to section "Measurement Equipment and
Accessories", item 3)
Frequency 500 MHz
Level 0 dBm
Phase noise at 500 MHz: < -100 dBc (1Hz) @ 10 kHz
< -110 dBc (1Hz) @ 100 kHz
< -120 dBc (1Hz) @ 1 MHz
Test setup:  Connect the RF output of the signal generator to the RF input of the
R&S FSH.
Signal generator settings: - Frequency 500 MHz
- Level 0 dBm
R&S FSH settings:
- [ PRESET ]
- [ FREQ : 500 MHz ]
- [ AMPT : 0 dBm ]
- [ SPAN : 10 kHz ]
- [ BW : RBW MANUAL : 1 kHz ]
- [ TRACE : TRACE MODE: AVERAGE ]
- Set marker to peak :
[MARKER: SET MARKER: PEAK ]
- Set marker mode to noise measurement
[MARKER: MARKER MODE: NOISE ]
Depending on the offset, refer to the table below for values of center
frequency, resolution bandwidth and reference level.
- [ FREQ : {Center}]
- [ AMPT : {Ampt}] ]
- [ BW : RBW MANUAL : {RBW}]
- [MARKER: DELTA: {offset}]
Evaluation: The phase noise is displayed in the marker field by the reading
´D: {offset} -xxx.x dBc/Hz´
Phase noise measurement settings
Offset Center
Frequency
RBW Reference Level a
R&S-FSH
(for information)
30 kHz 500.03 MHz 1 kHz 0 dBm 20 dB
100 kHz 500.1 MHz 10 kHz 0 dBm 20 dB
1 MHz 501 MHz 100 kHz -20 dBm 0 dB
Note: To obtain a precise measurement of the phase noise at high offsets the level used at the
R&S°FSH input is up to 20 dB higher than the reference level. To reduce the measurement time the phase
noise is measured with a small span around the frequency offset. This prevents the R&S°FSH from being
overloaded.