Sallen-Key polyphase filter design

Abstract

Present wireless receiver designs often make use of low intermediate frequency structures for signal reception. These topologies frequently apply polyphase filters for noise and image signal attenuation. When using active-RC implementations of single pole or direct synthesis structures, the number of operational amplifiers and thus power consumption becomes high. To confine the latter, a Sallen-Key based polyphase filter is presented in this paper which reduces the amplifier amount by one half. Furthermore, the system theoretic method used for circuit design is shown. Results are verified by Cadence simulation.