A 0.7 – 3.7 GHz six phase receiver front-end with third order harmonic rejection

This paper presents a highly linear receiver front-end operating from 700 MHz to 3.7 GHz with 3rd order harmonic rejection. It consists of a complementary low noise transconductance amplifier with capacitive cross coupling and negative gm current sources, a six phase current-mode passive mixer, and baseband transimpedance amplifiers providing programmable gain. The circuit has been fabricated in 65 nm CMOS technology with an active area of just 0.09 mm². It consumes 7.2 mA, excluding the six phase local oscillator generation, from a 1.2 V supply, achieving a third order harmonic rejection of 40 dB, and a noise figure of 3 to 4.5 dB at 52 dB gain. The out of band IIP2 and IIP3 at full gain is +55 dBm and +5 dBm, respectively.