Radar stealth and mechanical properties of a broadband radar absorbing structure

A non-magnetic broadband radar absorbing structure (RAS) composed of glass fiber composite and multilayer frequency selective surface (FSS) films was designed, with subsequently optimizing and manufacturing for radar absorbing and mechanical investigations. The results revealed that the proposed RAS exhibited −10 dB absorption from 8 GHz to 18 GHz at thickness of 3.5 mm, with a substantially broadened absorption bandwidth via dual absorption peaks. Due to the embedment of FSS films, the thermal-elastic stability of the structure was slightly enhanced while the flexural and impact resistance performances decreased owing to the effect of weak interface between the FSS films and composite laminates. In fact, the tensile performance of RAS, which was important for application under load bearing conditions, was not significantly compromised. The failure morphologies of the RAS were analyzed by scanning electron microscope (SEM) and the fracture mechanism was discussed.