Design of a Wide Band Thin Microwave Absorber

This manuscript proposes a wideband thin microwave absorber with 90% absorptivity. The unit cell of the proposed absorber contains two L shape patches with an inner ring conductor on the top of the FR4 substrate and copper laminates on the bottom surface. The absorber thinness is only 2 mm. This absorber has a wideband absorptivity response from 7.31 GHz to 10.7GHz without using any lumped circuit components. The maximum absorptivities of 99.71% and 99.9% are detected at 7.68 GHz and 10.01 GHz respectively. Several designed parameters are studied. The absorption characteristic of the proposed design absorber is observed by varying oblique incidence for TE and TM polarization. It is found that wideband absorption characteristics maintain up to 300 incidence angle for both TE and TM mode. In comparison to currently existing microwave absorbers, the proposed construction is extremely thin.