We propose a novel design procedure for a 2-D array of tapered dielectric structures for broadband and wide-incident-angle transmission. We exploit a stereolithography apparatus (SLA)-type 3-D printer to fabricate tapered dielectric samples. This technology eliminates the costly and complicated processes (e.g., perforation and etching) that are required in the fabrication of tapered dielectric structures. Specifically, we adopt the rigorous coupled wave analysis (RCWA) technique to extract the effective permittivity (EP) of a tapered dielectric unit structure. An optimization algorithm is employed to determine the ultimate optimal design parameters for the maximum transmittance. The free-space measurement is performed to evaluate the electromagnetic (EM) performance of designed samples. We demonstrate that a 2-D array of optimized tapered dielectric unit structures can exhibit enhanced transmission property in comparison to a half-wavelength dielectric layer and tapered dielectric structure without optimization, viz. above 60% transmittance over the entire Ka-band up to 60° of the incidence angle for both transverse electric (TE) and magnetic polarizations.
This work was supported in part by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (MSIT) under Grant 2020R1A2B5B01002251, in part by the NRF Grant through the Korea Government (MSIT) under Grant 2021R1A4A1030775, and in part by the Institute of Information and Communications Technology Planning and Evaluation (IITP) Grant through the Korea Government (MSIT) under Grant 2022-0-00704-001 (Development of 3D-NET Core Technology for High-Mobility Vehicular Service).
