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

Test ProceduresSMIQ5.3.4.5 Overvoltage Protection (if provided)Test equipment - Adjustable DC voltage source (Table 5-1, item 12)- Signal generator (Table 5-1, item 5)- Power amplifier (Table 5-1, item 13)Test setupMeasurement Connect an adjustable DC voltage source to the RF output socket ofthe SMIQ via a 50 Ω resistor or a signal generator with a subsequentpower amplifier with a power output of more than 1 W. Settings on SMIQ:- Frequency 100 MHz, unmodulated- Level -120 dBm Apply the DC voltage via the 50 Ω resistor. The overvoltage protection must respond at a voltage > 4 V and< 7 V for both polarities. Connect the signal generator to the RF output socket of the SMIQ viathe power amplifier and apply frequencies of up to RF max . Increasethe level at each frequency, starting with 0.1 W. The overvoltage protection should respond at an RF power of 1 Wat the latest.5.3.5 Spectral Purity5.3.5.1 HarmonicsTest equipment Spectrum analyzer (Table 5-1, item 2)Test setupConnect the spectrum analyzer to the RF output of the SMIQ.Synchronize reference frequencies of analyzer and DUT.Recommended settings on thespectrum analyzerNote: Reference level = test level + 3 dB, 10 dB/div.Span 0 Hz,Resolution bandwidth 1 kHz,Video bandwidth 30 Hz,Sample detectorThese values are typical values that are dependent on the analyzer used.The necessary spacing must be verified prior to the measurement.Recommended frequencies 300 kHz, 1 MHz, 5 MHz and as from 50 MHz according to Table 5-2Measurement Settings on SMIQ:- Test frequencies, unmodulated- Level Pcw max according to data sheet Settings on analyzer:ATTENUATOR AUTO LOW DISTORTION First measure the level of the fundamental as a reference. Then findsignals at twice and three times the carrier frequency. The harmonic spacing is the measured level referred to thefundamental (dBc = referred to the carrier).1125.5555.03 5.18E-9