Dispersion engineering of thick dielectrics via embedding meta-atoms for achieving wideband large-angle transmission...

Achieving large-angle electromagnetic(EM) wave transmission is crucial for communication, detection, and guidance but remains challenging, especially when using thick dielectric substrates, which can provide strong aerodynamic support and high temperature resistance. The most significant impact on practical application results is the narrow transmission bandwidth and sensitivity to incident angles. By incorporating Drude dispersion engineering, the effective permittivity becomes frequency-dependent, enabling dynamic manipulation of the electromagnetic response at different frequencies. This manipulation enhances the transmission bandwidth in two key aspects: firstly, it introduces an additional solid-air-like transmission channel at the low-frequency end; secondly, it nonlinearly adjusts the distribution of multiple half-wavelength resonance frequencies, bringing them closer. Furthermore, with the coupling effects provided by Lorentz-type resonant, adjacent resonance frequencies can be directionally shifted, which facilitates the merging of multiple transmission peaks into a continuous broadband. In this work, we propose a method to freely tailor the dielectric dispersion of thick dielectrics by embedding metamaterials consisting of metal wires and L-shaped metal patches. To demonstrate this idea, prototypes were designed, fabricated and measured. Fabricated prototypes show good agreement between measurements and simulations, validating the method. This opens what we believe to be new paths for wideband EM windows in next-gen communication, radar and electronic countermeasure systems.