SPICE-compatible stamps for semi-discrete approximations of Maxwell's equations

This article presents the formulation of equivalent circuit stamps derived from the semi-discrete form of Maxwell's equations. In particular, when a rectangular Yee's lattice is used for the spatial discretization of Faraday's and Ampere's laws, the stamps assume simple forms in terms of lumped circuit elements and dependent sources. It is shown that there is a very close relationship between the semi-discrete Maxwell's system and the mesh analysis formalism of Kirchhoff s voltage and current laws. Boundary conditions, including a first-order absorbing boundary condition, are extended to equivalent circuit descriptions. The utilization of the SPICE-compatible equivalent circuit stamp formalism for the numerical solution of Maxwell's equations using SPICE is illustrated for the case of the calculation of the resonant frequencies of a perfectly conducting, rectangular cavity resonator.