Wideband Low-Profile Luneburg Lens Based on a Glide-Symmetric Metasurface

Abstract

This paper presents a two-dimensional low-profile Luneburg lens that is designed by using a glide-symmetric metasurface. The entire lens consists of two mirrored metal plates with periodic metal pins, and the pins on one plate are glided exactly a half period of the unit cell compared with the pins on the other plate. The proposed design has not only a stable refractive index over a wide operating band but also no dielectric loss compared to other metamaterial-based lenses. In addition, it is easy to manufacture and can also largely reduce the production cost. The complete Luneburg lens is simulated in CST Microwave Studio, and the results demonstrate that the lens can work within 14 GHz-22 GHz, which is greater than 44% of the bandwidth. The measured results show that the lens also agrees well with the simulated lens. This lens antenna would be an excellent candidate for satellite communication applications.

On the Benefits of Glide Symmetries for Microwave Devices

“…These curves are more circular in the case of glide symmetry, especially as the frequency increases. This phenomenon was first reported in [13] and was later used for the design of planar lenses [60]- [62]. More details about these designs are provided in Section V.…”

“…The benefits of glide symmetries are not limited to holey structures. For example, glide-symmetric metallic pins also present advantages with respect to conventional pins, as demonstrated in [61], [62], [88]. Similar benefits were demonstrated in planar technologies [89]- [91].…”

Dispersion Analysis of Periodically Loaded Transmission Lines with Twist Symmetry Using the Mode-Matching Technique

“…Additionally, it has been demonstrated that glide-symmetric structures are less dispersive [12,13] and can provide a higher effective refractive index [13][14][15][16], effective permeability [17], and level of anisotropy [18], compared to their non-glide counterparts. These properties have been used to design planar lenses in [13,[19][20][21][22]. Furthermore, while the stop-band between the first two modes is suppressed in glide-symmetric structures, a large stop-band exists at higher frequency [23][24][25].…”

Three-Dimensional Broadband and Isotropic Double-Mesh Twin-Wire Media for Meta-Lenses

“…However, the designed lens exhibits strong anisotropy, which degrades the scanning performance of the lens. Alternatively, two-dimensional (2D)-graded index lenses can be realized using concentric dielectric cylinders [16,17] or mimicked with quasi-periodic structures [18][19][20][21][22][23] or geodesic surfaces [5,[24][25][26]. However, the scanning is reduced to one dimension in the 2D lenses.…”