Evaluation of an IQ demodulator

We evaluated an IQ demodulator aiming at the usage for the phase measurement of the reflected pulse from the accelerator structure test at Nextef. The characterization of the IQ demodulator was made by varying the input power level both for LO and RF input. We conclude that this device can be used for the identification of the reflected phase different by ±120 degrees depending on which cell the breakdown happens. The further evaluation of the device was tried with fitting the output (I, Q) in the complex plane but could not get an practical solution to calibrate the module over a dynamic range of 20dB.