Low-Loss Dual-Polarized Frequency-Selective Rasorber With Graphene-Based Planar Resistor

A novel dual-polarized frequency-selective rasorber (FSR) using an omnidirectional planar resistor based on graphene flake is presented in this article. The FSR exhibits a low-loss transmission window above an absorption band. It consists of a lossy layer and a lossless bandpass frequency-selective surface (FSS). In the lossy layer, a central symmetric graphene-metal hybrid structure is formed by connecting four metal strip-based resonant circuits with a square graphene flake. A low insertion loss transmission band is obtained by removing the resistance out of the parallel resonant circuits. Moreover, equivalent circuits are utilized to demonstrate the working mechanism. The proposed FSR exhibits a good absorption performance from 8.15 to 13.8 GHz, and a low insertion loss of 0.15 dB obtained at 16 GHz. Finally, a prototype FSR is fabricated and good agreement between the simulated and the measured results is obtained. The FSR has further advantages of avoiding the process of welding multiple lumped resistors per unit, thereby greatly reducing the number of lumped components and improving the planar integration of the structure.