Extreme Beam-forming with Impedance Metasurfaces Featuring Embedded Sources and Auxiliary Surface Wave Optimization

TL;DR

This paper introduces a novel design method for compact, passive impedance metasurface antennas with embedded sources, enabling extreme beam-forming and high efficiency through auxiliary surface wave optimization.

Contribution

It develops an end-to-end design framework using integral equation models for metasurfaces with embedded sources, achieving near-perfect aperture efficiency for complex beam-shaping.

Findings

Achieved nearly 100% aperture efficiency in beam-forming.

Enabled wide-angle and shared-aperture beam transformations.

Validated designs with full-wave numerical simulations.

Abstract

We present the end-to-end design of compact passive and lossless metasurface (MTS) antennas with integrated feeds. The complete low-profile system consists of a single-layered reactive impedance MTS printed on top of a grounded dielectric substrate, and is fed by sources which are embedded inside the substrate. An accurate and efficient volume-surface integral equation-based model of the device is developed, and used as the basis for the rapid optimization of its performance. The optimized designs leverage tailored auxiliary surface waves supported by the impedance MTS to distribute the localized source power across their apertures. This facilitates the realization of extreme field transformations such as wide-angle beam-forming or shared-aperture beam-forming, with nearly 100% aperture efficiencies. The procedure also allows for arbitrary beam-shaping with complete main beam and side lobe control. We also derive several feasibility-related constraints, which can significantly enhance the power efficiency as well as the bandwidth of the MTS antennas when they are implemented in practice. Full-wave numerical simulations confirm the effectiveness of the presented approach, as well as the extreme field transformation capabilities of the synthesized designs.