Quad-switch push-pull (QSPP) RF amplifier with direct, simultaneous modulation of phase and pulse position for spread-spectrum power applications

Abstract

We present a new RF power amplifier for spread spectrum applications, including wireless power transfer with low electromagnetic interference (EMI). The amplifier delivers half sine wave voltage pulses of either polarity through direct pushpull modulation of phase and pulse position. EMI is a concern not only from a regulatory perspective, but also in medical and other critical environments. The voltage pulses can be optimized by a variety of methods for specific spectral characteristics to create a current, and hence a high frequency magnetic field with a spread spectrum. The topology takes advantage of the inherent characteristics of GaN FET devices.