A triple-band CMOS class-E power amplifier for WCDMA/LTE applications

This paper presents a fully integrated triple-band CMOS class-E power amplifier (PA) for WCDMA (1.9 GHz) and LTE (1.8 GHz and 2.6 GHz) applications. The triple-band operation is achieved by activating selectively transistor cells and matching the transistor cells with low/high-band on-chip transformers for the three different frequencies. The PA is fabricated using a 0.18-μm CMOS process and has a chip size of 1.5 × 1.85 mm² including matching networks and transformers. This PA obtains output powers of 27.8/28.1/27.4 dBm at 1.8/1.9/2.6 GHz in continuous wave (CW) modes, respectively. The PA implemented to hybrid-EER structure satisfied the ACLR requirements up to 21 dBm for WCDMA (1.9 GHz) and up to 18 dBm and 16.3 dBm for LTE (1.8 GHz and 2.6 GHz) without any linearization technique.