GaNFET-Based High-Frequency Power Amplifier with FPGA-Driven PWM and Audio Codec Frontend for Piezoelectric Load

Abstract:
This paper presents a GaNFET-based high-frequency Class-D amplifier designed for piezoelectric applications. It integrates an FPGA-driven PWM modulator, sinc interpolation for upsampling, and noise-shaping quantization. The analog signal is digitized via an audio codec and processed through sinc interpolation and a noise-shaping quantizer to produce high-fidelity PWM suitable for GaNFET switching. The GaNFET H-bridge ensures efficient operation with reduced switching and conduction losses, while the FPGA enables precise timing critical for ultrasonic applications. Experimental validation demonstrates 92% efficiency and 1.46% THD, confirming suitability for precision ultrasonic drive systems through the combined benefits of high-resolution PWM, sophisticated noise shaping, and GaNFET switching precision.