Design & manufacturing of dielectric resonators via 3D printing

Abstract

Background: In recent years, the research of new materials and manufacturing methods for telecommunication and sensing applications has received significant attention. The demand for novel and high-performance dielectric resonators is increasing exponentially, and the research community is forced to design new radiating and measurement systems to satisfy market demands.Objective: The objective of this study was the application of two low-cost 3D-printing filaments, a pure commercial polymer, polylactic acid (PLA), and a PLA-based polymer reinforced with ceramic filler (Zirconia), to design dielectric resonators and check their suitability to use in a sensing application.Methods: Fused Deposition Modeling (FDM) was used to design and fabricate the 3D dielectric resonant prototypes. The filaments were characterized in terms of their thermal behavior, the mechanical stability determining the tensile properties of each material, and the quality of their printability. Both filaments were characterized in terms of dielectric properties by inserting 3D-printed bricks in a resonant cavity connected to a Vector Network Analyzer (VNA). Moreover, the prototypes were designed and simulated in electromagnetic simulation software. In the end, a VNA instrument was used to measure the printed dielectric resonators' reflection coefficient (S11).Results: The PLA and Zirconia dielectric resonators were successfully manufactured by the 3D printing technique. Both prototypes were designed, and a target frequency of ~ 2.45 GHz was attempted. The results obtained for both materials in terms of the size of the prototypes, the ease of manufacturing, the printability, mechanical stability, the cost per volume of each filament, and the bandwidth were used to compare and conclude their suitability for a sensing application.Conclusion: In conclusion, Zirconia-filled polymer has unique characteristics compared to conventional polymers, such as small size, higher permittivity, low losses, and very narrow bandwidth, consequently, a suitable material and manufactured prototype for a sensing application.