Design of Conformal Array of Rectangular Waveguide-fed Metasurfaces

TL;DR

This paper introduces an analytical design method for conformal metasurface arrays on curved surfaces, enabling efficient pattern tailoring without extensive full-wave simulations.

Contribution

It develops an approximate analytical model for conformal metasurfaces that accounts for curvature effects, facilitating design with optimization techniques.

Findings

The analytical model accurately predicts radiation patterns for small curvature conformal arrays.

The design method successfully creates metasurfaces with desired radiation characteristics.

Numerical simulations validate the effectiveness of the proposed approach.

Abstract

We present a systematic design method for a cylindrical conformal array of rectangular waveguide-fed metasurfaces. The conformal metasurface consists of multiple curved rectangular waveguides loaded with metamaterial elements\textemdash electrically small irises\textemdash inserted into the upper conducting walls of the waveguides. Each element radiates energy into free space to contribute to an overall radiation pattern. Thus, the geometry or electrical configuration of each of the individual metamaterial elements needs to be tailored to generate a desired pattern. In general, due to difficulties in modeling the effect of curvature, the design of conformal metasurface arrays has relied on full-wave simulations or experiments. In this study, we propose a design method utilizing the analytic model of a planar metasurface accounting for metamaterial elements' locations and orientations over a surface with curvature. Although approximate, we demonstrate that such an alteration along with the framework of dipolar modeling of planar elements can be used for the analysis of conformal arrays with small curvature. We then design a conformal array metasurface using the method combined with CMA-ES optimizer. Through numerical simulations, we confirm the validity of the proposed design method. Applications include the design of metasurfaces for radar, communications, and imaging systems for automobiles and airplanes.