A Low-IF/Zero-IF Reconfigurable Analog Baseband IC With an I/Q Imbalance Cancellation Scheme

A low-IF/zero-IF reconfigurable analog baseband IC embodying an automatic I/Q imbalance cancellation scheme is reported. The chip, which comprises a down-conversion mixer, an analog baseband filter, and a programmable gain amplifier, achieves a high image rejection of 55 dB without any calibration. It operates over a wide radio frequency range of 0.4-2.4 GHz, and has a cut-off frequency range of 0.3-30 MHz in zero-intermediate frequency (IF) mode and an IF range of 0.2-6 MHz in low-IF mode. The circuit in the receiver chain draws only 4.5-6.2 mA, and the clock generator including LO buffers draws 1.8-6.3 mA from a 1.2-V supply. The chip, implemented in 90-nm CMOS technology, occupies an area of 1.1 .