Topologies and Linearization of High Peak-to-Average Power Amplifiers for Digital Broadcast Radio Applications
Broadcast radio is changing from an analog medium based on frequency modulation (FM) to a full digital broadcast based on orthogonal frequency division multiplexing (OFDM). The high peak-to-average power ratio of the OFDM waveform requires different power amplifier topologies and a high degree of linearity. The research in this project analyzes current amplifier performance for digital radio broadcasting in the FM band, investigates new linearization techniques and explores new amplifier topologies. Key research aspects are improving linearity to meet spectral emissions requirements and increasing power added efficiency (PAE) for amplifiers broadcasting a hybrid waveform composed of both an FM and OFDM component that is increasing in injected power with the goal of an all digital OFDM waveform.