Multiresolution Channel-Select Filter With Ultrawide Frequency Coverage

A multiresolution channel select filter topology is proposed for implementing a digitally-tunable bandpass response with ultra-wideband tuning range. This filter is composed of a chain of bimodal filter stages with self-complementary periodic frequency response. The frequency response behavior of this filter, the effect of parasitics, and the nonlinearities are studied in detail. A four-stage implementation is presented which is based on p-i-n diode switches and covers dc-2.5 GHz in 16 equal bandwidth channels with a maximum insertion loss of 6.7 dB.