High-aperture-efficiency 3D printed Mikaelian lens antenna for sub-millimeter-wave emerging applications

In this article, a high-aperture-efficiency, cost-effective Mikaelian lens antenna for emerging sub-millimeter-wave applications is proposed. The lens is optimized to achieve a compact design. Full-wave simulations are used throughout the design process to optimize the lens volume and implement matching layers that improve aperture efficiency. A first prototype was fabricated using a low-loss, cost-effective epsilon Zetamix fused filament, compatible with 3D printing, on a modified Raise3D Pro2 printer. Significant discrepancies between the simulated and measured performance of the first prototype motivated the fabrication of a second, improved prototype, which was printed on a higher-precision Bambu Lab H2D 3D printer. Experimental results demonstrate a significant improvement in performance, with a maximum realized gain of 22.1 dBi measured at 29.5 GHz. The aperture efficiency remains above 70% up to 28 GHz and reaches a peak value of 85% in the 21.5–22.5 GHz frequency range. These results validate the proposed design methodology and demonstrate the potential of low-cost additive manufacturing for high-performance sub-millimeter-wave lens antennas.