Scattering Reduction Metasurfaces Using Circular Inter-Digitated Self-Phased Elements

This paper presents a circular inter-digitated (CID) self-phased (SP) element to design scattering reduction metasurfaces. Unlike using different building blocks to form checker-board patterns as in conventional approaches, we propose using only a single element to realize a reduction surface. The metasurface achieves scattering reduction by phase cancellation among elements. We use a constituent material in the dielectric layer supporting the element to obtain phase tuning capability. As the constituent material permittivity changes, the resonance wavelength of the element also changes, which results in a phase change. The proposed element design consists of a dual-circular ring, incorporating a meandered slot line, or an inter-digitated line, in between. The element can achieve polarization independent phase control with 300 degrees of tunable phase and less than 2 dB loss. We synthesize a prototype scattering reduction surface to verify the proposed element design. Our simulation results demonstrate that the proposed metasurface structure significantly reduces the broadside scattering by more than 10 dB at 12.8 GHz for a normally incident plane wave.