A new method to measure pulsed RF time domain waveforms with a sub-sampling system

This paper describes a new method that enables time domain pulsed RF measurements with any sub-sampling system. The method consists of replacing the FFT with a rectangular windowed short-time Fourier transform (STFT). The algorithm automatically extracts Fourier co-efficients within the pulses and the system does not need any trigger signal or clocking circuit. This minimal software modification enhances the standard Large Signal Network Analyzer (LSNA), enabling pulsed measurements without any hardware modifications. Our algorithm has been tested with a wideband amplifier at 1.5 GHz.