Thin EM Wave Absorber Metasurface Based on Artificial Magnetic Conductor

Abstract

Most of electromagnetics (EM) wave absorbers have been realized on some hard substrates. Therefore the use was limited only in the field of planar surfaces, while absorbing EM waves are required with various forms of field. In this paper, based on a principle of artificial magnetic conductor (AMC) used as a metasurface, a thin EM wave absorber composed of octagonal patch array is designed on a dielectric substrate of silicon with the relative permittivity of 5.7 and the thickness of 0.3 mm. The use of thin substrate for the absorber is necessary to have possibility and flexibility in surface of field with a non planar shape. To obtain high absorption rate of proposed wave absorber, resistive elements are incorporated into the patches and connecting to the adjacent patches. The characterization result shows that the reflection coefficient was up to 29.15 dB at the resonant frequency of 2.5 GHz for the value of resistive elements of $2100\ \Omega$, in which this is much higher than the result without resistive elements.