New Triple-Passband Bandpass Filter Using Multipath Stub Loaded Resonators

In this letter, the triple-passband bandpass filter (BPF) based on multipath stub loaded resonators is proposed. The filter has advantages of compact circuit size, high passband selectivity and low insertion loss. The multipath stub loaded resonators is designed to have tree resonant paths at 1.575, 1.8, and 2.4 GHz. The resonant frequencies and transmission zero can be easily controlled by tuning length for each resonant path in the multipath stub loaded resonators. The proposed triple-passband BPF is showing a simple configuration, an effective design method and a small circuit size.