A 1.5V 0.7-2.5GHz CMOS Quadrature Demodulator for Multi-Band Direct-Conversion Receivers

This paper presents an integrated quadrature demodulator with on-chip frequency divider implemented in a 0.13 mum CMOS technology. The mixer consists of a transconductance stage, a passive current switching stage, and an operational amplifier output stage. A complementary input architecture has been used to increase the transconductance for a given bias current. From 700MHz to 2.5GHz, the demodulator achieves 10dB DSB NF with 9-33 kHz 1/f-noise corner and 35dB of low frequency voltage gain. The total chip draws 20mA-24mA from a single 1.5V supply