Structurally architected perforated dielectric substrate via stereolithography 3D printing for low-loss angle-selective surfaces

For microwave components, 3D printing offers a rapid prototyping and cost-effective fabrication route; however, the inherently high dielectric loss of many 3D-printable materials often generates significant insertion loss in radio-frequency devices. This study addresses this limitation via a structural approach, uniquely enabled by additive manufacturing. A structurally architected perforated dielectric substrate is proposed to effectively reduce dielectric loss and applied as the supporting platform to fabricate an angle-selective surface (ASS). Numerical simulations revealed that the designed ASS exhibits a transmission coefficient of −0.6 dB under normal incidence, representing an improvement of over 2.6 dB relative to a counterpart employing a non-perforated substrate. The perforated substrate was fabricated using stereolithography (SLA) 3D printing, and the conductive patterns were realised using silver paste. Subsequently, an 11 × 11 array prototype was manufactured and experimentally characterised. The measured normal-incidence transmission coefficient was −1.3 dB, 1.9 dB higher than that of the non-perforated substrate-based ASS. These results demonstrate that structurally architected perforated dielectric substrates fabricated via SLA 3D printing offer a promising low-loss, lightweight, and cost-effective platform for angle-selective surfaces and related microwave components.