Characterization of baseband electrical memory in microwave devices using multi-tone measurement system

This paper presents the robust characterization of nonlinear microwave devices driven by broadband modulated multi-sine stimuli by using a refined multi-tone waveform measurement system. The substantial contribution comes from the capability of the measurement system to measure and average the time domain waveforms of adjacently modulated signals on a similar time scale for different modulation frequencies. The enhanced system demonstrates the ability of presenting the constant baseband (IF) loads across wide modulation bandwidth which is extremely imperative for the precise evaluation of inherent nonlinearity of microwave devices. The measurement system is later applied for the experimental investigations of baseband impedance variation effects on 10W GaN HEMT through the optimization scheme based on the simultaneously engineering of significant baseband components(IF1 and IF2) and higher baseband components(IF3 and IF4).