An Accurate and Efficient Finite Element-Boundary Integral Method With GPU Acceleration for 3-D Electromagnetic Analysis

An accurate and efficient finite element-boundary integral (FE-BI) method with graphics processing unit (GPU) acceleration is presented for solving electromagnetic problems with complex structures and materials. A mixed testing scheme, in which the Rao-Wilton-Glisson and the Buffa-Christiansen functions are both employed as the testing functions, is first presented to improve the accuracy of the FE-BI method. An efficient absorbing boundary condition (ABC)-based preconditioner is then proposed to accelerate the convergence of the iterative solution. To further improve the efficiency of the total computation, a GPU-accelerated multilevel fast multipole algorithm (MLFMA) is applied to the iterative solution. The radar cross sections (RCS) of several benchmark objects are calculated to demonstrate the numerical accuracy of the solution and also to show that the proposed method not only is free of interior resonance corruption, but also has a better convergence than the conventional FE-BI methods. The capability and efficiency of the proposed method are analyzed through several numerical examples, including a large dielectric coated sphere, a partial human body, and a coated missile-like object. Compared with the 8-threaded CPU-based algorithm, the GPU-accelerated FE-BI-MLFMA algorithm can achieve a total speedup up to 25.5 times.