Spherical Cap Resonator Array for Thin, Angular-Robust Absorption

The patent employs spherical resonators instead of planar or cylindrical structures. The spherical geometry provides superior angular robustness because it presents a consistent curvature to incident waves from any angle, maintaining stable resonance characteristics and absorption performance across a wide range of incidence angles, thereby resolving the contradiction between thickness and angular robustness.

The patent utilizes magneto-dielectric materials with specific electromagnetic parameters (high permeability and permittivity) to enhance absorption efficiency while maintaining reasonable thickness. By carefully selecting and tuning the material parameters, the absorber achieves both thin profile and high angular robustness, as the material properties compensate for the reduced thickness and maintain effective interaction with oblique incident waves.

The spherical shape of the resonators eliminates sharp edges and corners that cause diffraction effects. The continuous curved surface of the spheres prevents edge diffraction, while the spherical geometry supports well-defined resonant modes that can be precisely controlled through size and material selection, thus improving microwave performance without introducing harmful diffraction effects.

The patent uses an array of discrete spherical resonators rather than a continuous block of magneto-dielectric material. This discretization localizes the electromagnetic fields within individual spheres, preventing unwanted multiple resonances and edge diffraction effects that would occur in continuous structures, while still achieving broad bandwidth through careful design of the resonator array.