Recommendation on modeling wire grid reflector structures for sparse antenna generation

In order to reduce antenna mass, wire grid structures have been explored and developed to approximate the solid metal surface of conventional antennas. The method of moments is commonly employed to model and accurately calculate the characteristics of various wire grid structures. However, prior recommendations for approximating metal surfaces using wire grids based on the method of moments have been limited to antenna structures with planar metal surfaces. This paper elaborates on the procedures for approximating the solid metal surfaces of a reflector antenna using wire grids and introduces novel guidelines for modeling original wire grid structures. These guidelines facilitate the creation of sparse structures through the application of the optimal current grid approximation approach to that original wire grid. The detailed modeling steps described here enable the creation of wire grid reflector structures with adjustable geometric and wire grid parameters. The efficacy of the proposed guidelines is validated by applying them to reflector antennas operating in different frequency bands. Comparative analyses of the characteristics obtained for the wire grid structures against those obtained experimentally for solid metallic prototypes demonstrate favorable agreement, underscoring the effectiveness of wire grid structures designed using the presented guidelines. This study contributes to enabling antenna designers to efficiently design wire grid antenna reflector structures with reliable performance for sparse antenna generation.