Operating Manual R&S SMIQ - Volume 1 - Rohde & Schwarz

SMIQTest ProceduresPassive measurement ofVSWR with output levels ofSMIQ below -30 dBm Settings on SMIQ:- Test level- Frequency far from test frequency, unmodulated Settings on second signal generator:- Test frequency- Level 10 dBm Unscrew the VSWR bridge from the DUT and note down the levelmeasured at the analyzer as reference value. Screw on the bridge or directional coupler again and determine thenew level at the analyzer. The voltage ratio of test level to reference level is the outputreflection coefficient r of the DUT.The voltage standing wave ratio (VSWR) can be calculatedaccording to the formulaVSWR = (1+r)/(1-r)5.3.4.3 Settling TimeTest assemblyTest methodPreparation of measurementMeasurementConnect the spectrum analyzer (Table 5-1, item 2) to the RFconnector of the SMIQ.The spectrum analyzer is operated as a fast level meter with a span of0 Hz. A controller transfers the start and the stop level via the IEC bus.The analyzer is triggered by the positive edge on the EOI line of the IECbus. When the controller switches over from start to stop level, thesettling procedure is displayed on the screen of the storage analyzer. Synchronize the reference frequencies of the SMIQ and theanalyzer. Make IEC-bus and RF connections. Apply trigger connection to EOI line (pin 5) of IEC bus. Setting on SMIQ:- Test frequency 1GHz Settings on storage oscilloscope:- Time base 5 ms/div- Sensitivity according to video output of analyzer Settings on spectrum analyzer:- Reference level 10 dBm- Amplitude scale 10 dB/div- Resolution bandwidth 300 kHz- Video bandwidth 300 kHz- Span 0 Hz- Sweep time 50 ms,- Triggering externally by the positive edge at 1.5 V. First send the start and then the stop level from controller. The level characteristic from the trigger point is displayed on thescreen of the externally triggered analyzer. Repeat the measurement with the start and the stop levelinterchanged.Measure the following steps in both directions:1125.5555.03 5.15E-9