Rohde & Schwarz 1164.4391.03, Service Manual

Page: 44 / 254

Performance Test R&S FSP
116
4
.4556.82 1.16 E-1
Checking RF Attenuator
Test equipment: - Signal generator (refer to "Measurement Equipment", item 3)
Frequency 128 MHz
Maximum level 0 dBm
- Step attenuator (refer to "Measurement Equipment", item 11)
Frequency
128 MHz
Attenuation 0 to 80 dB in 10 dB steps
Attenuation accuracy < 0.1 dB
1
)
1
) If a step attenuator with lower accuracy is used, correction
of the measured attenuation is recommended.
Test setup:
Connect RF output of the signal generator to RF input of the step
attenuator.
Connect RF output of the step attenuator to RF input of the
R&S FSP.
Signal generator settings:
- Frequency 128 MHz
- Level 0 dBm
Step attenuator settings:
Attenuation 70 dB
R&S FSP settings:
- [ PRESET ]
- [ FREQ : CENTER : 128 MHz ]
- [ SPAN : 500 Hz ]
- [ BW : RES BW MANUAL : 1 kHz ]
- [ TRACE : DETECTOR : RMS ]
- [ BW : VIDEO BW MANUAL : 100 Hz ]
- [ AMPT : RF ATTEN MANUAL : 10 dB ]
- [ AMPT : -30 dBm ]
Reference measurement: Set marker to peak of signal:
- [ MKR : PEAK ]
Set reference to peak of signal:
- [ MKR : REFERENCE FIXED ]
Measurement
Step attenuator settings:
Attenuation { 80 dB - a
FSP
}
Refer to table below for values of a
ATT
.
R&S FSP settings:
- [ AMPT : RF ATTEN MANUAL : { a
FSP
} ]
- [ AMPT : {-40 dBm + a
FSP
} dBm ]
- [ MKR : PEAK ]
Refer to table below for values of a
FSP
, a
ATT
and reference level.
Evaluation:
The difference between the level of the input signal of the R&S FSP
and the reference (at 10 dB RF attenuation) is displayed in the marker
field by the reading ´Delta [T1 FXD]´.
a
ATT
80 dB 70 dB 60 dB 50 dB 40 dB 30 dB 20 dB 10 dB
a
FSP
0 dB 10 dB 20 dB 30 dB 40 dB 50 dB 60 dB 70 dB
Reference level
-40 dBm -30 dBm -20 dBm -10 dBm 0 dBm +10 dBm +20 dBm +30 dBm