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

In this paper, we report a novel shape synthesis method for multi-mode dielectric resonator antennas (DRA) that combines characteristic mode analysis (CMA) and a binary genetic algorithm (BGA). This feed-independent optimization forms a non-canonical dielectric body from tetrahedral elements, shaping the geometry to support the required modal resonant frequencies and quality factors. A feed network is then designed to excite the corresponding modes for matched and decoupled responses. 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.