Lossy parallel-plate line analysis using an unconditionally stable compact method

An unconditionally stable time-domain method with reduced grid size is proposed to deal with Maxwell's differential equations. The proposed method uses Yee's finite difference scheme in the space domain, and expands electromagnetic fields in a series of basis functions and treats them in a moment method procedure in the time domain. We use triangle basis functions and Galerkin's testing procedure to get an implicit formulation. At the same time, the analytical nature of the fields along the wave propagation direction is taken into consideration and the grid size can be greatly reduced. Compared with the traditional finite-difference time-domain (FDTD) method, the propose method notably improves computational efficiency.