Waveguide filters using T-shaped resonators

An enhanced waveguide E-plane bandpass filter using T-shaped resonators is presented. Characteristics of the proposed filter structure are analysed and investigated. The proposed filter with 4.5 % bandwidth is designed at 9.45 GHz, fabricated and tested. Its performance is evaluated through measurements, the experimental results obtained show that the proposed bandpass filter structures improve selectivity and size compared with those obtained using a conventional E-plane filter structure. A size reduction of more than 12 % was achieved and selectivity performance improved by more than 60 dB.