Design of triple-passband bandpass filter with interdigital resonators

A triple-passband bandpass filter is proposed. With the interdigital resonators embedded into the open-loop resonators, the bandpass filter with multiple passbands can be obtained. Moreover, by adopting the method of interdigital resonators, the passband with broader bandwidth on the higher frequency band can be obtained. The measured results of the fabricated filter match well with the electromagnetic simulation, therefore the feasibility of the proposed filter is approved.