Wideband Ultra-thin Metamaterial Absorber for Ku & K- Band Applications

This paper is based on the ultra-thin wideband absorber for Ku & K-band applications with a 40% fractional bandwidth. The bandwidth of the designed absorber is 8.1 GHz (15.7GHz to 23.8GHz) at absorptivity of more than 90% and 7.3 GHz (16.1 GHz to 23.4 GHz) at absorptivity more than 98%with a center frequency of 19.8GHz. The structure is a single dielectric layer of FR4 having a thickness of 1.6mm. The design of the proposed absorber is based on simple ring geometry with optimized ring width, split width and split angle. The absorber is able to maintain 63% of absorptivity at an incident angle of 45°. Also, the structure observes absorptivity reversal with the variation of the polarization angle from 0° to 90°. A simple miniaturized structure and single-substrate layer with wide bandwidth are the fundamental features of the proposed metamaterial absorber.