Efficient Synthesis of Passively Loaded Finite Arrays for Tunable Anomalous Reflection

TL;DR

This paper presents a design methodology for finite, passively loaded antenna arrays that can be tuned to achieve perfect anomalous reflection in arbitrary directions, validated through numerical and experimental results.

Contribution

It introduces an efficient, algebraic load optimization approach for synthesizing large-scale, tunable anomalous reflectors with purely reactive loads.

Findings

Achieved anomalous reflection into arbitrary angles with reactive loads.

Validated the design through numerical simulations and experiments.

Demonstrated applicability to large-scale practical reflectors.

Abstract

A design methodology for planar loaded antenna arrays is proposed to synthesize a perfect anomalous reflection into an arbitrary direction by optimizing the scattering characteristics of passively loaded array antennas. It is based on efficient and accurate prediction of the induced current distribution and the associated scattering for any given set of load impedances. For a fixed array of finite dimensions, the deflection angles can be continuously adjusted with proper tuning of each load. We study and develop anomalous reflectors as semi-finite (finite $\times$ infinite) and finite planar rectangular arrays comprising printed patches with a subwavelength spacing. Anomalous reflection into an arbitrary desired angle using purely reactive loads is numerically and experimentally validated. Owing to the algebraic nature of load optimization, the design methodology may be applied to the synthesis of large-scale reflectors of practical significance.