A 24 GHz IQ-demodulator with ultra-low amplitude and phase imbalance

This paper describes a 24 GHz quadrature demodulator (IQ-demodulator) using 65 nm bulk CMOS technology. The proposed IQ-demodulator consists of two direct down conversion mixers and a polyphase filter for 90° phase shifting. The two mixers are matched to 50 ohm by an on-chip bias-tee matching network with ESD protection. The parasitic inductance compensation technique is used to minimize the IQ imbalance. The proposed IQ-demodulator is measured with 5 dBm LO power. Measurement results show a peak conversion gain of 7.3 dB with IQ phase and amplitude imbalances of 0.1 dB and 6 degree, respectively. The total power consumption of the demodulator is 16 mW. The active chip area is 0.42 mm
²
.