Characterization of Near-Field Coupling Effects From Complicated Three-Dimensional Structures in Rectangular Cavities Using Fast Integral Equation Method

This paper characterizes the frequency domain near-field coupling effects from complicated three-dimensional transmission lines, monopole/dipole radiators, and printed circuit boards (PCBs) located in a metallic rectangular cavity with an efficient iterative fast Fourier transform-accelerated integral-equation method. The simulation method combines the rectangular-cavity Green's functions with the frequency-domain electric field integral equation, which is further accelerated by the extension of adaptive integral method for rectangular cavities. By using this method, the near-field coupling effects and internal field distributions are captured and compared with independent references for various structures, including transmission lines, monopole/dipole radiators, and PCBs in rectangular cavities. Numerical results show that strong couplings do appear at multiple resonant frequencies of the structures. In addition, this method can be further employed to mitigate and suppress near-field coupling effects in the optimization of electromagnetic compatibility/interference designs.