Novel switched-capacitor pseudo-N-path filter

Abstract

The letter presents novel fully stray-insensitive switched-capacitor (SC) pseudo-N-path filters based on the theory of wave-flow networks. N-path filters are well suited for the realisation of narrowband bandpass and bandreject filters. The two main drawbacks of N-path filters, i.e. unwanted mirror frequencies due to path mismatch, and clock feedthrough located in the passband, are overcome by applying the pseudo-N-path principle. The design procedure will be demonstrated using an example of a 6-path filter based on a 3rd-order highpass prototype filter.