Optimal design of broadband radar absorbing sandwich structure with circuit analog absorber core

Circuit analog (CA) absorbers have advantages of broadband radar absorption and feasibility in realizing the design blueprint. In this paper, a kind of radar absorbing sandwich structure (RASS) with rigid CA absorber core is proposed, which is capable of broadband absorption as well as load bearing. The numerical approach to predict the broadband reflectivity of CA absorber is introduced into an adaptive genetic algorithm (AGA) so as to derive the optimal RASS design within a certain frequency range. Furthermore, mechanical constraints including facesheet yielding, core shearing, and facesheet wrinkling, are incorporated into the optimization procedure to derive the optimal design of a one-side clamped RASS panel subjected to uniformly distributed loads. The results indicate that, when the layer number of lossy films is fixed, the radar absorbing performance (RAP) is not improved monotonically with the structure thickness, and by the present optimization procedure, an optimal structure thickness together with position, sheet resistance and geometry of the lossy films can be expected for such kind of RASS.