A Thin, Angle-insensitive, Broadband Microwave Absorber Based on Metamaterial

In this paper, we have presented a simple model for making thin, angle-insensitive, broadband metamaterial absorber in microwave frequency. The proposed structure consists of a square loop imprinted on a aluminum-backed dielectric substrate. Numerical results show that a -10dB absorption bandwidth from 4.77 to 9.52GHz has been realized under normal incidence. The distributions of electromagnetic field have been illustrated at the low-frequency peak of 5.4GHz and high-frequency peak of 8.0GHz to analyze the absorption mechanism of the proposed structure. And we find that the absorption dependent on the thickness of substrate and the length of square loop hugely. Moreover, the magnitude distributions of electric field along the direction of y-axis on proposed absorber has been presented with incident angles ranging from 0 0 to 60 0 . Because rotational symmetric properties of the structure, the performance of the absorber is insensitive to the angle of the incident waves, which indicated the prospect of future application in the field of microwave absorber based on metamaterials.