3D-Printed Dielectric Resonators for Quasi-TE112 Mode Singlets, Doublets and Dual-Mode Filters.

This paper demonstrates the use of a ceramic stereolithography-based additive manufacturing process to fabricate higher-order mode dielectric resonators. In this work, dielectric resonators with concentric rings around a combline rod structure are 3D-printed using alumina. The integration of the concentric rings for the use of the TE112 mode allows for a more compact cavity structure and a higher unloaded quality factor when compared to a simple dielectric combline resonator with a similar S-parameter response. The achievable improvements in quality factor for the TE112-mode resonators utilising concentric rings are compared through simulations and experimental results. The measured results demonstrate an increased average in the unloaded quality factor of Q(u) approximate to 2172 which is approximately 44%. Additionally, the application of the 3D-printed resonators is further demonstrated in a TE112 singlet, doublet, and dual-mode filter configuration.