With the advancement of high-power microwave (HPM) technology, there is a growing demand for HPM antennas with beam scanning capabilities.

This paper focuses on beam-scanning technology in the HPM field and proposes a novel circularly-polarized all-metal beam-scanning lens antenna based on the Risley-prism principle, aiming to address the challenges of wide-angle beam scanning and high power handling capacity (PHC).

By introducing circular slots and metamaterial structures into hexagonal units, a circular polarization orthogonal conversion efficiency(the conversion efficiency of incident left-hand/right-hand circularly polarized (LHCP/RHCP) waves to their orthogonal RHCP/LHCP waves) of over 99% at the central frequency and a continuous phase tuning range of 0° to 360° are achieved. After arraying, the two-layer lens, together with the radial line slot array (RLSA) antenna, constitutes the beam scanning antenna system. Specifically, the first lens converts the circularly polarized hollow beam radiated by the feed antenna into a solid beam while achieving a 25.66° beam-deflection synchronously. The second lens further deflects the beam, and two-dimensional beam scanning within a conical angle of ±60° can be realized by independently rotating the two layers of lenses.

A beam scanning lens antenna operating at 14.25 GHz with an axial length of 5.6λ is designed and simulated. During the scanning process, the gain varies within the range of 34.7–37.9 dB, the reflection coefficient remains consistently below −25 dB, and the maximum aperture efficiency exceeds 79%. The PHC of the beam scanning antenna exceeds 1 GW.

The antenna proposed in this paper exhibits excellent beam scanning performance and high PHC, demonstrating great potential for applications in the HPM field.