Analytical Design for Full-space Spatial Power Dividers Using Metagratings

TL;DR

This paper introduces a comprehensive theoretical approach for designing full-space spatial power dividers using metagratings, overcoming previous limitations and enabling versatile beamforming and power division functionalities without extensive numerical optimization.

Contribution

The study develops a modal expansion framework based on Floquet-Bloch theorem that relaxes previous design restrictions and allows for arbitrary spatial power dividing using metagratings.

Findings

Successfully eliminates unwanted scattering harmonics.

Enables realization of various functionalities like anomalous refraction and reflection-transmission power dividing.

Confirmed by numerical simulations aligning with theoretical predictions.

Abstract

We present a rigorous theoretical framework for designing full-space spatial power dividers using metagratings. In our study, the current restrictions of spatial power dividing platforms such as reflection-only performance, operating at normal incidence, and small reflection/refraction angles have been totally relaxed. A modal expansion analysis based on Floquet-Bloch (FB) theorem is established so that a discrete set of spatial harmonics is considered in both reflection and transmission sides of a compound metallic grating in which the unknown coefficients are calculated by applying proper boundary conditions. By eliminating the unwanted scattering harmonics, the proposed metagrating has the ability to realize different functionalities from perfect anomalous refraction to reflection-transmission spatial power dividing, without resorting to full-wave numerical optimizations. The numerical simulations confirm well the theoretical predictions. Our findings not only offer possibilities to realize arbitrary spatial power dividers but also reveal a simple alternative for beamforming array antennas.