900 MHz pulse-width-modulated class-S power amplifier with improved linearity

Summary form only given, as follows. This paper presents a novel 900 MHz pulse-width-modulated current-mode class S power amplifier (PA). The complete class-S amplifier is characterized using clipped WCDMA signals. For the 5 MHz signal, the measured spectrum at the amplifier's output shows good EVM of 12% (approx. 1.5% degradation assumed for class-S PA) and also meets the 3rd Generation Partnership Project adjacent channel leakage ratio (3GPP ACLR) requirements within 9 dB input power range. The capability to support large signal bandwidths is demonstrated, using an 80 MHz WCDMA signal.