Rohde & Schwarz R&S FSH - Page 28

Performance Test R&S FSH
1145.5973.82 1.4 E-11
Checking the frequency response
For the measurement of the frequency response, the value at 100 MHz for each reference level setting is
used as the reference. The reference level influences the RF attenuation (RF attenuation = +10 dBm +
reference level).
Test setup:  Connect the RF output of the signal generator to the input of the
divider.
 Connect output 1 of the divider to the power sensor / power meter.
 Connect output 2 of the divider to the RF input of the SA..
Signal generator settings: - Frequency {f
in
} *
- Level -4 dBm
Determine the output power of the signal generator with the power meter.
Adjust the output power of the generator until the power meter shows
-10 dBm.
R&S FSH settings:
- [ PRESET ]
- [ AMPT : Ref_Lev*) ]
- [ SPAN : 100 kHz ]
- [ BW : MANUAL RES BW : 10 kHz ]
- [ TRACE : DETECTOR : RMS ]
- [ FREQ : CENTER : {f
in
} * ]
- [ SETUP : Hardware Setup: Low Noise]
*) Refer to table under “Performance Test Report” for values of Ref_Lev
and f
in
.
If the a RF preamplifier is installed, its frequency response has to be
checked also. To switch it on please enter:
- [ SETUP : Hardware Setup: Preamp: ON ]
Reference measurement:
 Determine signal level L
powermeter
.
 Set the marker to the peak of the signal.
- [ MARKER: SET MARKER: PEAK ]
The signal level L
is displayed by the level reading of the marker.
Ref
100MHz
= L - L
powermeter
Measurement
Signal generator settings: - Frequency {f
in
}
Refer to table under “Performance Test Report” for values of {f
in
}.
Power meter settings:
Determine the signal level L
powermeter
. To achieve higher accuracy,
compensating the frequency response of the power sensor is
recommended.
R&S FSH settings:
- [ FREQ : {f
in
} ]
Refer to table under “Performance Test Report” for values of {f
in
}.
 Set the marker to the peak of the signal.
- [ MARKER: SET MARKER: PEAK ]
The signal level L
is displayed by the level reading of the marker.
Evaluation: The frequency response can be calculated as:
Frequency response = L
- L
powermeter
- Ref
100 MHz