Mehri Borhani Kakhki - Electrical and Computer Engineering Faculty, Semnan University, Semnan, Iran
Majid Afsahi - Electrical and Computer Engineering Faculty, Semnan University, Semnan, Iran
Elham Ghadamyari - Electrical and Computer Engineering Faculty, Semnan University, Semnan, Iran

In this paper two novel structures of the frequency selective surface (FSS) are designed to improve the wide-band stealth performance of radar absorbing materials (RAM) at Ka-band and Ku-band. First structure is a thin planar electromagnetic absorber consisting of a Frequency Selective Surface (FSS) layer that ring and crossed dipoles are sandwiched between two layers and used as absorber in the Ku frequency band from 12.1 to 16.2 GHz. Second structure is a thin planar electromagnetic absorber consist of two Frequency Selective Surface (FSS) layers. The layers are separated by dielectric material. A ring and crossed dipoles are used in the design of these layers. Crossed dipoles are in the upper layer and ring is in the lower layer. This structure is used as absorber in the ka frequency band. In both structures the layers are backed by the ground plane and separated by foam material from it.

Frequency Selective Surface (FSS), thin absorber, radar absorbing materials (RAM)