122 Keysig ht N9923-90001 User’s GuideCalibration for NA, CAT, and VVM ModesVerifying Calibration and Jumper Cable IntegrityVerifying Calibration and Jumper Cable IntegrityAfter calibrating, it is important to verify that the calibration is good. Whenusing a jumper cable, also verify that the cable is of high quality.Verify a Calibration— Connect a LOAD standard at the calibration reference plane (wherecalibration standards were connected). This may be at the end of thejumper cable or at FieldFox PORT 1 connector.— InCATMode,select Return Loss.— InNAMode,select S11 with Log Mag format.— For frequencies lower than 9 GHz, observe the trace on the FieldFoxscreen:—Lower than 35 dB indicates a GOOD calibration.—Higher than 30 dB indicates that you should recalibrate.Verifying Phase Accuracy— Connect a LOAD standard at the calibration reference plane (wherecalibration standards were connected).— In NA Mode, select a S11 Reflection with Polar or Smith Chart format.— Because all LOAD standards have delay, you should see a small amount ofphase rotation as a function of frequency. In general, the measurementresult should agree with the characteristics of the calibration standard.Test the Jumper CableWith the LOAD standard still connected, move the jumper cable whileobserving the trace.— If the measurement trace is relatively stable, the jumper cable is of goodquality.— If you observe significant movement in the peaks of the measurement tracewhen moving the cable (>5 dB), the jumper cable may need to be replaced.
