A heterodyne low IF receiver front end for Short Range Communication

This paper presents a radio frequency front end of 5.8GHz dedicated short range communication receiver, utilizing a low-IF heterodyne architecture, which is necessary to solve the image problem and I/Q mismatches. A LC tank that is used as load of LNA can tune the resonant frequency more accurately than specific process allows. A simple but effective voltage bias for the first RF mixer is proposed, which helps reduce the complexity. The implementation satisfies the requirement of low power, large dynamic, simplicity and so on. The chip prototype is fabricated in 0.18um CMOS technology and occupies an active area 0.1mm². It achieves sensitivity about -61.6 dBm. The RX data rate of complete chip, including receiver, transmitter and digital, can achieves 256 kbps. The RF front end consumes 10.8 mA and supplies by 1.8 V.