Simultaneous Polarization Conversion and Anomalous Reflection with Anisotropic Printed-Circuit-Board (PCB) Metagratings

TL;DR

This paper introduces a semianalytical design method for PCB-based metagratings that achieve simultaneous polarization conversion and beam steering, utilizing anisotropic tilted dogbone meta-atoms for enhanced control.

Contribution

The work presents a novel semianalytical synthesis scheme incorporating anisotropic tilted dogbone meta-atoms for improved polarization and wavefront manipulation in PCB metagratings.

Findings

Experimental verification of the design framework.

Enhanced polarization and beam control demonstrated.

High diffraction efficiency achieved.

Abstract

We present a semianalytical synthesis scheme for designing realistic printed-circuit-board- (PCB) based metagratings (MGs), capable of simultaneous beam steering and polarization conversion. These low-profile structures, comprised of sparse periodic arrangements of subwavelength polarizable particles (meta-atoms), oriented by insightful analytical models leading to fabrication-ready designs, have gained growing interest in recent years, demonstrating exceptional diffraction engineering capabilities with very high efficiencies. Herein, to facilitate cross-polarization coupling, we introduce a tilted dogbone meta-atom, going beyond the popular vertical (loaded wire) or recently proposed horizontal (dipole) configurations used in common PCB MG manifestations at microwaves, strictly susceptible to either transverse electric (TE) or transverse magnetic (TM) fields, respectively. As shown, the anisotropy introduced by the in-plane rotation of the dogbones, integrated into the MG analytical model in the form of a rotated dipole line, serves as an additional degree of freedom that can be leveraged to nonlocally manipulate the polarization and trajectory of the incident fields. Verified experimentally, the resultant semianalytical synthesis framework enables valuable physical insights, opening the door to integration of efficient anisotropic MGs in applications requiring both polarization and wavefront control, such as satellite, radar and advanced antenna systems.