Design of Dielectric Resonator Antenna Using Dielectric Paste

In this publication, the use of a dielectric paste for dielectric resonator antenna (DRA) design is investigated. The dielectric paste can serve as an alternative approach of manufacturing a dielectric resonator antenna by subsequently filling a mold with the dielectric paste. The dielectric paste is obtained by mixing nanoparticle sized barium strontium titanate (BST) powder with a silicone rubber. The dielectric constant of the paste can be adjusted by varying the BST powder content with respect to the silicone rubber content. The tuning range of the dielectric constant of the paste was found to be from 3.67 to 18.45 with the loss tangent of the mixture being smaller than 0.044. To demonstrate the idea of the dielectric paste approach, a circularly polarized DRA with wide bandwidth, which is based on a fractal geometry, is designed. The antenna is realized by filling a 3D-printed mold with the dielectric paste material, and the prototype was found to have an axial ratio bandwidth of 16.7% with an impedance bandwidth of 21.6% with stable broadside radiation.