A fully integrated 2.4 GHz CMOS high power amplifier using parallel class A&B power amplifier and power-combining transformer for WiMAX application

A new structure integrated power amplifier with watt-level output power is presented in a standard 0.18 mu m CMOS process for WiMAX applications. A parallel cascode class A&B power amplifier with optimized widths is proposed to increase linearity and efficiency simultaneously. A novel interleaved per power combiner is proposed for increasing output power that combines output current of two similar class A&B power amplifiers. Proposed interleaved transformer heightens coupling factor compared to typical transformer. The proposed power amplifier with 33 V power supply provides maximum output power of 32.5 dBm and power added efficiency of 37.9% at 2.4 GHz operating frequency. The proposed power amplifier exhibits high output power of 32.3 dBm at 1 dB compression point. The simulation results for proposed PA with modulated OFDM signal show that -31 dB error vector magnitude at the average power of 25 dBm can be achieved. (C) 2013 Elsevier GmbH. All rights reserved.