US Patent 7538596 Low distortion quadrature mixer and method therefor

A mixer (114) includes an input amplifier (620) and a barrel shifter (640). The input amplifier (620) has an input for receiving an input signal, and first through fourth output terminals respectively providing first through fourth current signals. The barrel shifter (640) has first through fourth input terminals for respectively receiving the first through fourth current signals, first through fourth control terminals for respectively receiving first through fourth clock signals, and first through fourth output terminals for respectively providing positive and negative in-phase output signals and positive and negative quadrature output signals.