High-Gain Broadband All-Metal Discretized Gradient Luneburg Lens Design

To address the demand for high-gain, multi-beam antennas in millimeter-wave communication systems, this paper proposes an all-metal metamaterial-based Luneburg lens structure. By utilizing a discretized metallic pillar array to modulate the equivalent gradient refractive index distribution and dynamically adjusting the equivalent permittivity through the height parameters of metallic pillars, a gradient refractive index coverage of 1–1.5 is achieved. A 29-layer lens structure is designed based on Schrank’s equal-thickness layer method, and validated through CST electromagnetic simulations. Results demonstrate that in the 13–17 GHz frequency band, the antenna maintains a stable gain of 15.7–17.7 dBi, with an H-plane half-power beamwidth (HPBW) below 6.1°, and effective suppression of sidelobe levels. The design integrates the advantages of high conductivity from the all-metal structure, low profile, and broadband characteristics, offering a cost-effective, high-performance multi-beam antenna solution for millimeter-wave communication systems.