3D‐printed ceramics with engineered anisotropy for dielectric resonator antenna applications

C. D. Morales,C. Morlaas,A. Chabory,R. Pascaud,M. Grzeskowiak,G. Mazingue

doi:10.1049/ell2.12234

Abstract

In this letter, we study the design of three-dimensional (3D)-printed ceramics exhibiting anisotropic dielectric permittivities at microwave frequencies for dielectric resonator antenna (DRA) applications. The anisotropy is engineered by using periodic structures made up of subwavelength asymmetric unit cells filled with zirconia and air. Ceramic samples with uniaxial anisotropy are designed, 3D-printed, and measured. Birefringence up to 8 is achieved by controlling the volume fill rate of the unit cell. Besides, a single-fed circularly polarised (CP) DRA that relies on a 3-D-printed uniaxial anisotropic ceramic is proposed in the 2.45 GHz ISM band. Its simulated and measured reflection coefficient, axial ratio, and realised gain patterns are in good agreement, thus demonstrating the possibility of exploiting 3-D-printed anisotropic ceramics for DRA applications.

Highlights

The dielectric resonator antenna (DRA) has been extensively studied to take advantage of it’s reduced size, ease of excitation, high radiation efficiency and wide bandwidth [1]
We study the design of three-dimensional (3D)-printed ceramics exhibiting anisotropic dielectric permittivities at microwave frequencies for dielectric resonator antenna (DRA) applications
If the fabrication of heterogeneous DRAs with complex shapes has so far been limited by traditional manufacturing methods such as tooling, machining, or moulding, recent advances in three-dimensional (3D)printing technologies are opening up new perspectives

Summary

Introduction

The dielectric resonator antenna (DRA) has been extensively studied to take advantage of it’s reduced size, ease of excitation, high radiation efficiency and wide bandwidth [1]. It allows great flexibility in its design by modifying its shape or dielectric properties to control, for instance, its impedance bandwidth or radiation characteristics. It has been proposed to control the effective permittivity of DRAs by structuring the 3D-printed material. Subwavelength unit cells consisting of both air and dielectric are periodically 3D-printed so as to obtain a material which effective dielectric permittivity is controlled by the volume fill rate of its unit cells. All these DRAs use engineered isotropic dielectrics whereas additive manufacturing may allow to obtain anisotropic dielectrics that can provide an additional degree of freedom in the design of DRAs [6]

Methods

Conclusion