A Versatile Switched-Mode Large-Signal GaN-Based Low-Distortion Arbitrary Waveform Generator

Abstract

In a multitude of industrial and biomedical applications, the need for arbitrary waveform generators is essential, serving the purpose of load characterization and excitation, among others. Historically, these generators have had limitations in terms of voltage, current, and frequency output, primarily related with constraints associated with the power devices and circuit topologies. However, notable advancements in semiconductor technology have introduced a new era, enabling the creation of highly versatile waveform generators capable of superior performance, and extended operational capabilities. In this article, a versatile AWG based on switched modules is proposed. In contrast to the previous ones, whose implementation was based on linear amplifiers, it enables arbitrary waveform generation, higher efficiency, and very low output impedance. In addition, it is also presented as a novelty that the voltage in each of the modules is different, following a digital to analog converter (DAC) structure, which allows us to obtain a lower total harmonic distortion (THD) in the output waveform than with conventional methods. The design will take advantage of wide band gap devices to be able to switch in the MHz range to achieve a high bandwidth. Furthermore, in addition to the design and implementation of a high-performance generator, a comparative analysis between the conventional and the proposed DAC-based modulation pattern is performed based on a comparative analysis of the THD and switching losses.