Shape Synthesis and 3D Ceramic Printing of Non-canonical MIMO Dielectric Resonator Antennas

TL;DR

This paper introduces a shape synthesis method for multi-mode dielectric resonator antennas using characteristic mode theory and genetic algorithms, enabling the design of complex, non-canonical shapes for improved MIMO antenna performance.

Contribution

The paper presents a novel shape synthesis approach that optimizes dielectric resonator shapes based on modal properties without needing excitation feeds, demonstrated through 3D printed MIMO antennas.

Findings

Achieved >20 dB isolation between ports in MIMO DRA

Successfully synthesized and fabricated complex non-canonical shapes

Demonstrated operation at 2.45 GHz with optimized modal properties

Abstract

In this paper, we report a shape synthesis method for multi-mode dielectric resonator antennas (DRA) using characteristic mode theory (CMT) and a binary genetic algorithm (BGA). By including the antenna's characteristic modal responses (resonance frequencies and quality factors) in the cost function, the shape synthesis process is conducted without including excitation feeds. Through the optimization procedure, a non-canonical dielectric body is formed from tetrahedral elements to support the required modal properties. As a demonstration of the proposed design approach, two three-mode MIMO DRAs are synthesized from both a rectangular and a cylindrical volume to operate at 2.45 GHz. The synthesized MIMO DRA's complex shape (based on rectangle) is then fabricated using Nanoparticle jetted zirconia. A combination of probe and slot feeds are employed to excite the desired modes. Due to the orthogonality of the characteristic modes and the careful design of the feeding network, isolation $>20$ dB is achieved between all ports.