A 2.4-GHz Fully CMOS Integrated Transmitter for 802.1lb Wireless LAN

Abstract

Featuring a direct-conversion architecture, a 2.4-GHz radio-frequency (RF) transmitter frontend for 802.11b wireless LAN (WLAN) is implemented in 0.18-mum CMOS technology. Direct-conversion architecture minimizes the on-and-off-chip components required and provides a low-cost and low-power solution. The transmitter incorporates two low-pass filters (LPFs), a single-sideband (SSB) mixer, a power amplifier driver and a divide-by-two circuit for quadrature LO generation. The transmitter provides a gain control of 12 dB in 3-dB steps and an output 1-dB compression of 7.7 dBm while delivering a nominal output power of 0 dBm. The chip consumes 40 mA from a 1.8-V supply and occupies an area of 2.5 times 2 mm2 including pads