Hybrid FDTD Method for Studying Electromagnetic Coupling Effects of Transmission Line Networks

This letter proposes a novel hybrid finite-difference time domain (FDTD) method, which combines the full-wave FDTD (2, 4) method with a thin-wire model, a transmission-line equation, the Kirchhoff's law, and a two-port equivalent-circuit FDTD model, where antenna–cable coupling model and modified nodal analysis method are also implemented through a set of proper boundary conditions. In our method, both coaxial cable and thin-wire antenna are treated together without geometric meshing for full-wave simulation, and all the coupling processes among fields, transmission line equations, and circuit loads are carried out at the same time step. Such hybrid method is verified by comparing with both PSPICE and traditional FDTD method, and good agreements are obtained. Further, the proposed method is successfully applied to predict the transient electromagnetic responses of some complex transmission line networks in a vehicle-based metallic shelter.