An ultra-thin absorber in microwave range: 50 GHz band-width, absorption over 80 %

An ultra-thin microwave absorber with a 34 GHz bandwidth more than 90% absorption in the frequency range of 33.5 GHz - 67.5 GHz, and 50 GHz bandwidth, more than 80 % absorption is proposed. The functionality of the device was analyzed using an equivalent circuit model (ECM) by exploiting the impedance matching concept in the transmission line theory. By changing the chemical potential of the graphene, following manipulating characteristics of the graphene surface conductivity, can achieve several absorption responses in wideband range frequencies. Additionally, the proposed absorption is stable in a wide range of incident angles. These advantages make the proposed absorption attractive for several applications such as optical sensors and detectors.