High resolution wideband calibration procedure for RF time-domain measurement of non-linear devices

This paper proposes a high resolution wideband calibration procedure for RF time-domain measurement of nonlinear devices. This calibration is based on the use of wideband multi-sine signal and is applied to a 4 channel Track and Hold Amplifier (THA) based measurement setup. The absolute magnitude and phase calibration is performed with a calibrated coherent interleaving sampling oscilloscope as reference. The new calibration procedure without any IF calibration assumption allows a 10 kHz resolution over 3 GHz bandwidth. A 40 W GaN high power amplifier, driven by a pulsed RF signal at the input, is characterized with this time-domain measurement setup. The fully calibrated measurement setup has the capability to give an accurate visualization of time-domain distortions on input/output voltage and current waveforms within the pulse. Calibrated rising and falling transitions of the pulse are also exhibited.