Abstract-Inhomogeneous anisotropic cloaks can be approximated by more realizable homogeneous and isotropic material layers at the expense of their bandwidth and angular dependence. Aiming at applications to a monostatic Radar, we propose a scheme to design broadband cylindrical cloaks with minimized backscattering RCS. The cloak is composed of a few layers of concentric magnetic materials, with optimized parameters using a genetic algorithm (GA). We also examine extensively the parameters in the optimization, including the initial population and the relationship of required discretization with the operation frequency. It has been demonstrated that, through a proper designed optimization, the bandwidth can exceed 80% for nondispersive cloaks and 4% for dispersive cloaks.

Abstract-An accurate and efficient computational approach is presented for analyzing radiation characteristics of large antenna arrays with radome. This approach is based on the hybrid finite elementboundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA). Unlike the conventional singledomain FE-BI-MLFMA, the whole domain of the antenna array with radome is separated into many disconnected domains. A large free space area unavoidable in the single-domain FE-BI-MLFMA is eliminated in this multi-domain FE-BI-MLFMA formulation, thus the number of unknowns is greatly reduced in the presented multi-domain FE-BI-MLFMA approach. Different from the single-domain FE-BI-MLFMA, many integral equations are required in this multi-domain FE-BI-MLFMA. The numerical experiment shows that the presented multi-domain FE-BI-MLFMA is more efficient than the singledomain one while maintaining the same accuracy. A whole complicated system of a slotted-waveguide array with radome mounted on an aircraft is analyzed to further demonstrate the generality and capability of the presented multi-domain FE-BI-MLFMA.

Abstract-It has been widely verified that the hybrid finite element -boundary integral -multilevel fast multipole algorithm (FE-BI-MLFMA) is a general, efficient and accurate method for the analysis of unbounded electromagnetic problems. A variety of fast methods of FE-BI-MLFMA have been developed since 1998. In particular, the domain decomposition methods have been applied to FE-BI-MLFMA and significantly improve the efficiency of FE-BI-MLFMA in recent years. A series of fast domain decomposition methods (DDMs) of FE-BI-MLFMA have been developed. These fast DDMs can be roughly classified into two types: Schwarz DDMs and dual-primal finite element tearing and interconnecting (FETI-DP) DDMs. This paper will first give an overview of the DDMs development of FE-BI-MLFMA. Then a uniform, consistent, and efficient formulation is presented and discussed for these fast DDMs of FE-BI-MLFMA. Their computational complexities are analyzed and studied numerically.