Shared meta-aperture system for the frequency-induced reconfigurable multiple beams

Abstract

We demonstrate the perfect synthesis of multiple beams with different radiating states at dual frequencies through a shared meta-aperture system, consisting of a checkerboard meta-lens with two kinds of gradient meta-atoms distributed in a diagonally staggered manner and a polarization converting meta-mirror possessing periodic skew double-headed arrow array. The co-linearly polarized (co-LP) waves reflected by the inner surface of the checkerboard meta-lens would be twisted into the cross-LP counterparts by the meta-mirror and then penetrate the checkerboard meta-lens to form the high-purity cross-LP directive multi-beams at one frequency. Meanwhile, the other polarization orthogonal meta-array over the outer surface of the checkerboard meta-lens would also be capable of transforming the released cross-LP fields back and create the co-LP multi-beams at another frequency. Especially, the frequency sensitivity of such shared meta-aperture system is discussed through comparing different sets of the synthesized multiple beams, and the multi-functional meta-surface coating over the checkerboard meta-lens will fundamentally determine the overall radiating patterns and the operating bandwidth. In addition, the proposed design through integrating composite functional meta-surfaces also possesses the merits of generating high-polarization purity multiple beams at different frequencies, thus should pave the way for building up more advanced shared-aperture meta-radiators with highly efficient connections in the contemporary wireless communications.