CMOS linear high performance push amplifier for WiMAX power amplifier

Abstract

In this work a novel and efficient approach is proposed to optimize the linearity and efficiency of power amplifiers used in mobile WiMAX applications. A linear and high performance push amplifier is designed and implemented in 0.18μm CMOS technology to enhance the linearity of a class-E switched-mode power amplifier. The proposed push amplifier consists of two sections; analog and switching sections. The analog section provides required linearity and the switching section guarantees satisfying total efficiency level. Each block is designed and optimized to meet required specifications. The core power amplifier which is a class-E switched-mode power amplifier is also designed to have maximum possible efficiency. The implemented circuit is simulated using HSPICERF and TSMC models for active and passive elements. The proposed power amplifier provides a maximum output power of 25dBm and a power added efficiency (PAE) as high as 48% at 2.5GHz operation frequency and supply voltage of 1.8V. At 1dB compression point this PA exhibits 23dBm of output power with 42% PAE and 4.5% EVM which was appropriate for 64QAM OFDM signals.