Radio-frequency performance comparison of several H-plane rectangular waveguide filters loaded with circular dielectric posts

Abstract

The study presents a radio-frequency performance comparison between several H-plane geometry filters based on rectangular waveguide technology. The basic all-metal filter of resonant cavities is compared with filters loaded with circular dielectric resonators, either in propagative or evanescent mode. The use of these resonators is claimed to reduce the length of the filter, increase the rejection band until the first spurious frequency and to improve the voltage magnification factor (VMF), at the cost of increasing the losses. Therefore, in order to properly assess and quantify the possible advantages of these filters, an accurate analysis of six of them has been developed. All the filters have been designed to have the same electrical response, and the length, losses, rejection band, VMF, and fabrication cost for all the filters are compared.