Scanning characteristics of metamirror antennas with sub-wavelength focal distance

TL;DR

This paper explores the beam scanning capabilities of metamirror antennas with sub-wavelength focal distances, demonstrating their practical potential and similarities to traditional short-focus reflectarrays through numerical and experimental analysis.

Contribution

It introduces the concept of sub-wavelength focal distance metamirror antennas and analyzes their scanning characteristics, showing they perform comparably to short-focus reflectarrays.

Findings

Metamirrors can scan beams up to 24 degrees.

Scanning ability is similar to short-focus reflectarrays.

Metamirrors are practically penetrable and invisible outside the operating frequency.

Abstract

We investigate beam scanning by lateral feed displacement in novel metasurface based reflector antennas with extremely short focal distances. Electric field distributions of the waves reflected from the antenna are studied numerically and experimentally for defocusing angles up to 24 degree. The results show that despite their sub-wavelength focal distances, the scanning ability of metamirrors is similar to that of short-focus reflectarrays (focal distance about several wavelengths). In addition to offering a possibility to realize extremely small focal distances, metamirror antennas are practically penetrable and invisible for any radiation outside of the operating frequency range.