An EDGE/GSM quad-band CMOS power amplifier

Abstract

Although Si CMOS PAs for mobile applications have demonstrated specification-compliant performance over the last several years, Si CMOS has not been widely employed in cellular PA applications due to certain inferior properties of its power capability, PAE, and breakdown to its counterparts such as GaAs and SiGe BJTs. However, research conducted in the past decade has enabled commercially available cellular switching CMOS PAs for constant envelope modulation such as GSM applications. This successful implementation of a GSM PA called forth a demand for a combination of linear EDGE operation with GSM operation in order to increase data rate up to 384kb/s while using legacy infrastructures. The challenges of implementation of a dual-mode CMOS PA arise from required linearity for high peak-to-average-power ratio, which forces the PA to operate at power back-off from the P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> and results in inevitable low efficiency. Although a CMOS EDGE/GSM PA was reported in the past, the application was intended for Class-E3 operation. The presented PA is an EDGE/GSM dual-mode, quad-band CMOS cellular application PA satisfying the requirement for power Class-E2 operation.