Ultra-Wideband Polarization Independent Absorber Based on Square Ring Structure with Nonuniform Ring Width

In this paper, the square ring structure with the load resistor is used as the loss layer to achieve the purpose of absorbing. The load resistor is used to broaden the absorption band width. The simulation results show that the reflection coefficient is less than -10dB from 3.5 GHz to 13.8 GHz. In order to obtain a wider absorption band width, the number of the dielectric layer is increased, and the result is obtained. The reflection coefficient is less than -10 dB in the frequency range of 1.83 GHz to 18.2 GHz and the bandwidth ratio is 1:9.95. Moreover, at the lowest frequency, the thickness of the structure is only 0.096 λ.