Slow-wave H-plane filter with improved frequency characteristics and reduced size

In this paper, a new partial H-plane filter with half-wavelength resonators and periodic slow-wave structure is presented. The proposed filter makes use of the slow-wave effect to improve the frequency characteristics and considerably reduce the filter length. Using partial H-plane waveguides reduces the filter's cross section to one-quarter of that of a conventional E-plane filter. Although because of their compactness, the insertion loss of the proposed H-plane filters is larger than that of the E-plane filters, they have lower cost and are mass producible. Also by using the periodic slow-wave structure the stop-band slope has been improved and the length has been reduced by 22 percent. These partial H-plane filters have been designed along with coaxial to partial H-plane waveguide transition.