Millimeter-Wave Thin Lens Using Multi-Patch Incorporated Unit Cells for Polarization-Dependent Beam Shaping

Abstract

This paper describes a millimeter-wave thin lens that exhibits different beam-shaping characteristics depending on the polarization of the incident waves. The proposed unit cell topologies, which use multiple rectangular patches and rectangular-slotted grids, enable thinner (= 0.05λ 0 ) and smaller (= 0.168λ 0 ) features than in previous polarization-dependent lenses. An appropriate set of the proposed unit cells is shown to cover a tunable phase range of 180° with respect to one polarized wave but have an almost-zero tunable range of phase shifts with respect to another polarized wave. Thus, using this unit cell set for x-polarized incident waves, the proposed lens operates as a convex lens, whereas for y-polarized incident waves, the lens operates as a frequency selective surface. This confirms that gain variations of 13 dB or more can be differentiated according to the polarization of the incident waves on the lens, supporting polarization-dependent beam-shaping capability as a function of the polarization of incident waves.