Design of a Wide Stopband Microstrip Bandpass Filter With Interdigital Resonators

In this letter, a novel microstrip bandpass filter (BPF) with interdigital resonators is presented. With the interdigital resonators and shorted asymmetrical coupled-lines, a wide bandwidth with sufficient rejection level can be achieved easily. A full-wave electromagnetic simulator IE3D is used, and the prototype of the BPF is fabricated and measured. Comparisons of simulated results and experimental data are shown; moreover, good match validates the proposed filter.