Lossy Material EBG Phased Array Antenna

The patent introduces an electromagnetic band-gap (EBG) structure as an intermediary element between the antenna elements and the substrate. This EBG structure acts as a mediator that suppresses surface waves generated by the high dielectric constant substrate, thereby preventing scan blindness while allowing the substrate's mechanical robustness and processing precision advantages to be retained. The EBG structure is periodically arranged and coupled with the antenna elements to create a band-gap that blocks the harmful surface wave propagation.

The patent modifies the parameters of the EBG structure, specifically using a split-ring resonator design with optimized geometric parameters (inner radius, outer radius, gap width, and orientation angle). By carefully tuning these parameters, the EBG structure suppresses surface waves while minimizing unwanted interactions with the antenna elements. The split-ring configuration with specific dimensional ratios creates a band-gap that targets surface wave frequencies without generating significant higher-order modes.

The EBG structure serves as a mediator that decouples the relationship between substrate dielectric constant and surface wave generation. This allows the system to use high dielectric constant substrates (which provide mechanical robustness and environmental stability) while the EBG mediator suppresses the surface waves that would otherwise limit bandwidth and scan volume. The periodic EBG structure creates an electromagnetic band-gap that prevents surface wave propagation regardless of the substrate's dielectric properties.