Rohde & Schwarz ZVB 14, Service Manual

Page: 18 / 198

Performance Test R&S ZVB
1145.1078.82 1.8 E–4
Checking the Output Linearity
Instrument:
Spectrum analyzer (see Chapter “Test Equipment“, Item1)
Test cable (see Chapter “Test Equipment“, Item7)
Test setup: Connect the spectrum analyzer to port 1(port 2 to port 4)
Spectrum analyzer settings:
Note:
Synchronize the reference oscillators in the spectrum analyzer and in the
R&S
®
ZVB :
– [
PRESET ]
– [ FREQ : f
GEN
*]
– [ SPAN : ZERO SPAN ]
– [ BW : MANUAL RES BW : 100 Hz ]
– [ MARKER : DETECTOR : RMS ]
– [ AMPT : REF LEVEL : 5 dBm ]
– [ Mode : ALC : On ]
* For measurement frequencies, see Performance Test Report {fGEN}.
R&S
®
ZVB settings:
– [ Preset ]
– [ Meas : Wave Quantities: a1 Src Port 1
(a2 Src Port 2, a3 Src Port 3, a4 Src Port 4)]
– [ Sweep : Sweep Type : CW Mode :
CW Frequency : {f
GEN
*} ; Power : {l
GEN
*} ]
– [ Sweep : Single : Restart ]
* For measurement frequencies {fGEN} and levels {l
GEN
}, see
Performance Test Report
Measurement: Read the spectrum analyzer’s marker values (level L) .
Calculation: The measured values are referred to the level at the R&S ZVB setting of
–10 dBm.
Calculating the generator level linearity:
Level linearity = L – L
@–10dBm
– step width (in dB)
Step width = l
gen
– (–10 dBm) (reference)