Design of Ceramic Dielectric Waveguide Filter based on Equilateral Triangle Resonator

In this paper, a six-order cross-coupled ceramic dielectric waveguide filter (CDWF) based on equilateral triangle resonators is introduced. It is composed of a regular hexagonal cavity which can be divided into six equilateral triangles. The filter exhibits two transmission zeros outside the passband that ensure its out-of-band suppression is greater than 50 dB. Simulation results show that the insertion loss is less than 0.1 dB and the return loss is less than 19 dB within the operating frequency range of 3.4-3.6 GHz. The ceramic dielectric used here has the dielectric constant of 20.3 and thickness of 5 mm. Thus, it has the advantages of compact size, excellent frequency selection and out-of-band rejection.