Compact S-shaped resonator loaded waveguide bandpass filters

A novel class of E-Plane, all-metal-insert filter structure with improved stopband performance and compactness using S-shaped resonators has been proposed. The structure can be easily realized with a metal insert within a standard rectangular waveguide. The proposed waveguide bandpass filter has been designed and simulated at 9.45 GHz. The proposed structure maintains the low-cost and mass producible characteristics of E-plane filters while achieving significant size reduction.