A Fully Integrated CMOS Class-E Power Amplifier for Reconfigurable Transmitters with WCDMA/WiMAX Applications

This paper presents a dual-band CMOS power amplifier (PA) using class-E topology for Wideband Code Division Multiple Access (WCDMA) at 1.9 GHz and Worldwide Interoperability for Microwave Access (WiMAX) at 2.6 GHz applications. The fully integrated PA consists of an input balun, a driver stage, a power stage, and two output transformers. To operate the dual-band PA, common-gate amplifiers having on-off apparatuses in power stage and matched transformers for 1.9/2.6 GHz are employed. The PA is designed and fabricated in a 0.18-μm CMOS technology and has a chip size of 1.5 × 1.85 mm2 including all pads. When driven by continuous wave (CW) signals, the output power and the efficiency reach 28.1/27.4 dBm and 37.8/31.6% at 1.9 GHz and 2.6 GHz, respectively. The average output powers of the hybrid-EER based TX system 21 dBm for 3.84 MHz WCDMA and 12 dBm for 5 MHz WiMAX, while also meeting stringent linearity specifications without using any linearization methods.