A novel W-band E-plane bandpass filter with compact size

This paper presents a novel W-band E-plane bandpass filter using E-plane resonators. Two pairs of transmission zeroes are designed to locate in the lower and upper stopbands respectively. Simulated studies are carefully conducted to demonstrate the proposed design method. The locations of transmission zeroes determine the operating frequency band of the designed filter. The transmission zeroes in the lower and upper stopbands greatly improve the out-of-band rejection levels. An example has been fabricated. This kind of filter has the advantage of very compact sizes in comparison with the conventional E-plane waveguide filters.