A Novel Method to Characterize Dispersion Effects in Multiharmonic for AlGaN/GaN HEMTs

This research proposes a novel method to characterize the dispersion effects in multiharmonic for AlGaN/gallium nitride (GaN) high-electron-mobility transistors (HEMTs), including trap effect and self-heating effect. In this method, a double-pulse test is designed to decouple the surface and bulk trap effects and the self-heating effect, thus extending the characterization of trap states from non-operating region to operating region. Additionally, the corresponding model is proposed. The trap model considers the traps in different locations and the asymmetric time constants of charging and discharging. A thermal subcircuit is used to model the self-heating effect. A complete process of characterization and parameter extraction for dispersion effects in multiharmonic is proposed. The proposed model is integrated into an advanced SPICE model for HEMT (ASM-HEMT) and accurately predicts <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i>–<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i>, RF small-signal, and large-signal harmonic characteristics, which is helpful in the design of high-efficiency power amplifiers.