Analysis and design of RC polyphase filters - input impedance, output termination, component mismatch effects, flat-passband filter design

摘要

This paper analyzes first-, second- and third-order RC polyphase filters; these are important components used for image rejection and in quadrature signal generation circuits in the analog front-ends of wireless transceivers. We clarify their input impedance and the effects of output termination, parasitic capacitance, and component mismatches. We also propose a design algorithm for a flat-passband second-order filter.