Impact of non-idealities on passive polyphase filter performance

A Polyphase Filter (PPF) is a kind of complex filter that avoids generating image frequency in a heterodyne transmitter. Its properties allow to achieve required selectivity, difficult or even impracticable with real filters in integrated circuits. However, its performance is notably affected by non-idealities although some of the most important have not been thoroughly analyzed previously in literature. In this paper, the impact of the most critical non idealities for a PPF are evaluated, such as mismatch or parasitics. Moreover, some design guidelines are given to minimize these undesirable effects.