3-D-Printed Single-Feed 45°-Polarized Waveguide-Based Antenna With Designable Concave Depth

This letter presents an X-band 45° polarization shaped beam antenna with designable concave depth implemented using metal 3-D printing. The key innovations include: A dual-waveguide antenna aperture enabling concave depth control via superposition of difference and sum patterns is proposed, and a compact waveguide power divider is designed to provide the desired amplitude ratio and phase difference between the two waveguide apertures, effectively adjusting the mode ratio between the difference and sum beam patterns. The radiating waveguides are twisted by 45° without changing phase centers to realize 45° polarization. Three prototypes with different pattern concave depths are fabricated using metal 3-D printing and experimentally verified. Within the operating band from 8.4 GHz to 9.4 GHz, the pattern concave depths of −5.6 dB to −6.9 dB, −7.9 dB to −9.1 dB, and −12.2 dB to −13 dB are realized, respectively, with corresponding gains higher than 6.2 dBi, reflection coefficients below −12 dB and cross-polarization levels below −15 dB. This work provides a promising solution of 45°-polarized antenna with a designable pattern concave required by customized beam coverage and corresponding array implementations.