Additively Manufactured Wideband High‐Gain Circularly Polarized Horn Antenna With Integrated PGM Lens and Dielectric Polarizer for Millimeter Wave Applications

ABSTRACT This paper presents a low‐cost, wideband, high‐gain circularly polarized horn antenna system realized through additive manufacturing. The proposed design integrates a three dimensional‐printed pyramidal horn antenna with a phase‐graded metasurface (PGM) lens and a dielectric polarizer (DP). The PGM lens, composed of cuboidal unit elements, is engineered based on near‐field phase transformation principles to enhance directivity and gain. The DP, featuring an air‐cavity slab configuration, enables effective linear‐to‐circular polarization conversion over a broad frequency range of 25.4–38 GHz. Circular polarization is achieved through axial rotation (ϕ = ±45°) of the DP at the horn aperture, generating left‐hand circular polarization and right‐hand circular polarization, respectively. The antenna demonstrates a 3 dB axial ratio bandwidth of 35.66% (26–37.4 GHz) and a 1 dB gain bandwidth of 42.13% (25.36–38 GHz). A prototype has been fabricated using additive manufacturing techniques, and measured results exhibit close agreement with simulations. The proposed antenna system offers a compact, cost‐effective, and high‐performance solution suitable for synthetic aperture radar applications in weather monitoring.