EM Design and Analysis of FSS-based Composite Broadband Radar Absorbing Structure

EM design and performance analysis of FSS-based composite broadband radar absorbing structure (RAS) is presented in this paper. In this design hybrid FSS unit is used where square patch and cross dipole are arranged in the diagonal direction. The square patch resonates at lower frequency side while cross dipole resonates at higher frequency side that leads to broadband characteristics. The EM analysis of proposed FSS-RAS is carried out using commercial HFSS software. The total thickness of FSS-RAS is optimized to be 3.8 mm for better EM absorption characteristics. The proposed FSS-RAS is observed to exhibits broadband absorption characteristics from 6 GHz to 21.7 GHz w.r.t. -10 dB reflection loss. Moreover, the EM characteristics is found to be polarization independent up to 50° incidence angle. Such FSS-RAS can potentially be used over leading wing edge of aircraft to reduce its radar signature.