| PhD Seminar

Name of the Speaker: Mr. Mohit Sharma (EE21D012)
Guide: Prof. Amitava Das Gupta
Venue: CSD-308 (Conference Hall)
Date/Time: 14th August 2024 (Wednesday), 2:30 PM
Title: Compact Modeling of GaN HEMT to capture Memory Effects in Power Amplifier

Abstract :

The rapid advancement of wireless communication systems, particularly driven by the introduction of 5G and 6G networks, has resulted in a paradigm shift that prioritizes linearity over efficiency. Consequently, the need for highly efficient RF power amplifiers (PAs) that can be effectively linearized becomes paramount. GaN based power amplifiers provide better efficiency, gain, and thermal performance when compared to alternate semiconductor technologies.

One of the primary challenges faced in optimizing RF power amplifiers is the inherent static non-linearity that arises from intermodulation distortion, giving rise to spectral regrowth in bands adjacent to the modulated signal. Another challenge in power amplifier design is memory effects (dynamic non-linearity) caused by time variations in their transfer characteristics, wherein the output signal depends not only on the current input sample but also on the past input. Memory effects mainly arise from trapping and de-trapping phenomena and self-heating in GaN HEMT.

Achieving an optimal balance in key power amplifier specifications, like linearity, output power, and power added efficiency, is a challenging task due to their complex trade-offs. Due to the presence of non-linearity in PA, accurate compact modeling is critical for the design, optimization, and linearization of power amplifiers. Standard compact models of GaN HEMT fail to adequately capture effects such as charge carrier trapping and self-heating. This research delves into the intricate dynamics of GaN HEMT RF power amplifiers, with a specific focus on memory effects and non-linearity. The goal of this research work is to develop a physics-based compact model of GaN HEMT that captures the non-linearity and memory effects.