Thin EM wave absorber composed of octagonal patch array and its characteristic measurement

In this paper, the development of thin electromagnetic (EM) wave absorber and its characteristic measurement are presented. The absorber is developed based on a textured surface structure of octagonal patch array which is loaded with surface resistor. The octagonal patch is employed as a unit cell which is intended to operate whereby at the resonance frequency of resistively textured surface. Each unit cell which has the substrate width of 14.4mm consists of an octagonal shape of patch with the width of 5.178mm. Here, the surface resistor are incorporated midway in between the adjacent patches to reduce the amount of backscatter from the absorber. The textured surface structure of octagonal patch array is deployed on a single-sided 3.2mm thick FR4 Epoxy dielectric substrate. From the result of experimental characterization, it shows that the reflection characteristic of absorber with 453Ω of surface resistor loading upon the incident wave is up to 34dB at frequency of 2.78GHz where this is 10dB better than the absorber without surface resistor loading.