▎ 摘　　要

NOVELTY - Hertz (Hz) to terahertz (THz) ultrathin dielectric -graphene based broadband coherent absorber (100) comprises a reflector, a substrate, and a resonator. The reflector is a graphene patch acting as back reflector plane resulting in zero transmittance and in addition provides coherent perfect absorption in the radio and microwave frequency regions up to 0.1 THz. The substrate is an ultratin dielectric slab assembled above the reflector with a guided wavelength and high relative permittivity that reduces size of the absorber along with cost constraints and acts as the fabry-perot cavity. USE - The absorber is useful for covering radio and entire microwave frequency spectrum extending to lower terahertz regime. ADVANTAGE - The absorber: covers the radio and entire microwave frequency spectrum extending up to terahertz frequency region with tunability; solves the issue of simultaneous broadband absorption in the radio, microwave and terahertz frequency spectrum; and reduces size and cost constraints, respectively. DESCRIPTION OF DRAWING(S) - The figure shows a front view of the Hz to THz ultrathin dielectric-graphene based broadband coherent absorber. 4Circular graphene top layer 5Cylindrical resonant cavity 100Absorber