A 65 nm CMOS - Stacked Folded Fully Differential (SFFD) PA structure for W-CDMA application

Abstract

This paper presents a 65 nm CMOS-power amplifier (PA) designed for mobile communications.The PA is based on a new structure, the stacked folded fully differential (SFFD) which is inspired by a push-pull structure. The PA is designed for the UMTS W-CDMA standard which requires linearity from -20 dBm to 24 dBm output power. The power amplifier provides 31 dBm output power with 26% of power added efficiency (PAE) at 1.95 GHz. The linear gain is 20 dB and the compression point (OCP1) is 25.6 dBm. In order to meet the UMTS W-CDMA requirements, the PA is linear until 24 dBm, which is the maximum output power required by this standard.