Loss-Optimized Reconfigurable Nonlocal Metasurface-aided Cavity Antenna

TL;DR

This paper introduces a reconfigurable cavity-fed metasurface antenna with wide-angle beam steering capabilities, utilizing a novel synthesis framework that accounts for nonlocal effects and minimizes losses, demonstrated at 10 GHz.

Contribution

It develops a volume surface integral equation-based synthesis method that accurately models nonlocal mutual coupling and incorporates tunable unit cell characteristics for precise far-field control.

Findings

Achieved 80-degree beam steering range at 10 GHz

Demonstrated stable beam steering with excellent simulation-measurement agreement

Minimized Ohmic losses through integrated resistance-reactance modeling

Abstract

This paper presents the design and experimental demonstration of a reconfigurable cavity excited nonlocal metasurface antenna capable of wide angle dynamic beam steering. The antenna is synthesized using a volume surface integral equation based framework that rigorously captures nonlocal mutual coupling among metasurface unit cells. To ensure physical consistency, the numerically characterized resistance and reactance relationship of the tunable unit cells is directly incorporated into the synthesis, enabling precise far-field synthesis while minimizing Ohmic losses. The proposed approach is applied to a 10 GHz cavity fed metasurface antenna composed of 24 independently controlled varactor-loaded unit cells. Numerical simulations and near-field measurements demonstrate stable beam steering with a range of 80 degrees across broadside with excellent agreement between measured and simulated radiation patterns. These results confirm the effectiveness of the proposed framework for the realization of compact, reconfigurable cavity-excited metasurface antennas.