Theoretical analysis for systematic design of flexible broadband radar absorbers using the least-square method

By taking into account the facts that thick dielectrics are required for low frequency absorbers, that thick dielectrics are not always flexible, and that targets are not always planar, an efficient tool for the systematic design of flexible broadband radar absorbers using the least-square method is presented in this paper. Two approaches for designing the physical model of the absorber are presented. The first one consists of resistive square loops deposited on top of a dielectric, and the second one consists of metallic square loops associated with lumped resistors. More than 90% of absorption rate is obtained in the required bandwidth for both transverse electric and transverse magnetic polarizations with the two approaches and achieving a performance of operational bandwidth to thickness ratio of 7.69. Finally, the required dimensions of flexible absorbers in some low frequency bands are given in order to show the versatility of the approach. © 2018, Electromagnetics Academy. All rights reserved.