Realization of arbitrary biaxial metamaterials enabled by aninterleaved metallic patch–rod structure

This Letter describes a method for synthesizing arbitrary biaxial metamaterials based on an interleaved metallic patch-rod structure. By tailoring the patch lengths and rod spacing, the effective permittivity tensor (ε_x, ε_y, ε_z) can be independently engineered while maintaining <i>μ</i>≈1. The suggested structure exhibits nearly dispersionless, low-loss electromagnetic behavior by operating in the deeply subwavelength regime. The homogenization model is validated through full-wave simulations that show excellent agreement between the synthesized and equivalent bulk media. Although our approach has been demonstrated in the microwave region, it is scalable to terahertz and optical frequencies and hence represents a general framework for designing anisotropic media with a customizable biaxial response.