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

Abstract

This paper demonstrates the use of a ceramic-based stereolithography additive manufacturing process in the fabrication of higher-order mode dielectric resonators. In this work, dielectric resonators with concentric disks around a combline rod structure are 3D-printed using alumina. The integration of the concentric disks for use of the TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">112</sub> 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 TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">112</sub> -mode resonators utilising concentric disks are compared through simulations and experimental results. The measured results demonstrate an increased average in the unloaded quality factor of Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>u</i></sub> ≈ 2172 which is approximately 44%. Additionally, the application of the 3D-printed resonators is further demonstrated in a TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">112</sub> singlet, doublet, and dual-mode filter configuration.