3-phase active-RC Tow-Thomas biquad complex filter

Quadrature signal system, which has an I-channel and a Q-channel, is widely used in analog baseband signal processing for wireless communication system. This sort of system needs a four-phase signal consisting of I-positive, expositive, I-negative, and Q-negative, so it needs a large area. A balanced three-phase analog signal processing has been proposed, and this system can realize an equivalent functionality to the fully-balanced system in smaller chip area. In this paper, a three-phase complex filter is proposed. The proposed circuit can reduce total resistance by 10%, total capacitance by 25%, and power consumption by 22% compared with four-phase conventional one.