Optimization of the design of radar-absorbing composite structures using response surface model with verification using scanning free space measurement

In this paper, we propose an optimization method for the design of radar-absorbing structures (RAS) made of fiber reinforced plastic structures using a response surface model and a verification method using a scanning free space measurement (S-FSM) system. The two kinds structures designed were an RAS with a layer of carbon nanotubes (CNT) and an RAS with a periodic patterned carbon paste layer. In the optimal design, the objective function was set so that the absorbing frequency bandwidth had the maximum value, in order to have stealth functionality in the X-band. The RAS with CNT layer had a higher minimum reflection loss than that with carbon paste layer, and the absorbing frequency bandwidth was lower. Two specimens were fabricated on the basis of the analysis results, and the design results were verified by evaluating their electromagnetic performance using an S-FSM system capable of measuring reflection loss. As a result, it was confirmed that not only the electromagnetic performance of the specimen but also the defects caused by the manufacturing process could be detected using the S-FSM.