Bandwidth reconfigurable microwave bandpass filter

A design approach for microwave bandpass filter (BPF) with bandwidth reconfigurability is presented. The proposed design employed varactor-tuned microwave resonators for realization of bandwidth reconfigurable BPF. Compared to the reported design methodology, the presented approach aims for the design of the reconfigurable BPF with relatively wide bandwidth tuning range, as well as low in-band insertion loss. Furthermore, the filter selectivity remains almost unchanged while the fractional bandwidth varies. The proposed design approach is experimentally verified through the demonstration of a coplanar-waveguide BPF design.