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

SMIQTest Procedures5.3.24.2 Additional Modulation Frequency ResponseTest equipment, test setup and testmethod as aboveMeasurementTest setup Two frequency response measurements are performed,the first one with DISTORTION OFF, the second with thebandwidth measurement setting. The additional frequency response sought is thedifference between the first and second measurement. Connect signal generator to the Q input of the SMIQ. Terminate the I input with 50 Ω.Measurement As above for I input.5.3.24.3 Residual CarrierTest equipment Spectrum analyzer (Table 5-1, item 2)Test setupMeasurement Connect the spectrum analyzer to the RF output of the SMIQ. Terminate the I and the Q input with 50 Ω. Settings on SMIQ:- Test level 0 dBm- Test frequency 400 MHz, 1.472 GHz and 4.4 GHz- DISTORTION CHARACTERISTIC LISTSwitch on SELECT LIST...TEST,DISTORTION ON- Select OFF in the menu VECTOR MOD/STATE Settings on analyzer:- Center frequency = test frequency, span = 1 MHz- Reference level = test level- Scale 10 dB/div First measure the unmodulated level as a reference. Switch on vector modulation (STATE ON) and measure the residualcarrier. The residual carrier in dBc is the level of the residual signal foundreferred to the output signal of the DUT without modulation(dBc = referred to the carrier). This value must be about thetypical value (