# Beamforming with metagratings at microwave frequencies: design procedure and experimental demonstration

## TL;DR

This paper presents a design and experimental validation of microwave metagratings with minimal degrees of freedom for beam steering, demonstrating their effectiveness and analyzing factors influencing their bandwidth.

## Contribution

It introduces a detailed design procedure for reflective metagratings with one degree of freedom per diffraction order and provides experimental results validating their performance.

## Key findings

- Successful fabrication of three metagratings demonstrating prescribed diffraction patterns
- Experimental results closely match full-wave simulations
- Analysis of factors affecting bandwidth and strategies to enhance it

## Abstract

As opposed to metasurfaces, metagratings represent themselves sparse arrangements of scatterers. Established rigorous analytical models allow metagratings to overcome performance of metasurfaces in beam steering applications while handling less degrees of freedom. In this work we deal with reflective metagratings that have only as few as one degree of freedom (represented by a reactively loaded thin wire) per each propagating diffraction order. We present a detailed design procedure and fabrication of three experimental samples capable of establishing prescribed diffraction patterns. The samples are experimentally studied in an anechoic chamber dedicated to radar-cross-section bistatic measurements and results are compared with three-dimension full wave numerical simulations. We identify and analyze factors affecting operating frequency range of metagratings, suggest a strategy to increase the bandwidth.