Wideband Image-Rejection Circuit for Low-IF Receivers

A wideband image-rejection circuit for GSM/EDGE low-IF receivers includes a reference signal source and digital correction circuit that compensate I/Q gain, phase, and frequency response mismatch. The chip integrates an LNA, mixers, PGAs, LPFs, and fractional-N synthesizer in a 0.25μm BiCMOS process and achieves 50dB IRR over the entire signal bandwidth at 200kHz IF