A LO-leakage auto-calibrated CMOS IEEE802.11b/g WLAN transceiver

This paper presents a fully integrated CMOS IEEE 802.11b/g WLAN radio transceiver chip with a novel local oscillator (LO) leakage auto calibration scheme. The transceiver chip is based on direct-conversion transmitter and receiver architecture and integrated in 0.25mum CMOS process. The noise figure is less than 5dB in a receive path. The inherent LO-leakage of direct-conversion transmitter is cancelled perfectly by using the proposed auto calibration method. The consumption currents of the receiver and transmitter are 120mA and 110mA at 2.5V power supply, respectively. Many kinds of cards and APs, which is made of this radio chip and homemade BB+MAC chip, have come into market.