Circuit-based FDTD method for transient analysis of mutually coupled system

The circuit-based FDTD method for transient analysis of a mutually coupled system is presented. To speed up the transient analysis, the reluctance matrix is introduced. We provide how to generate the sparse reluctance matrix with guaranteed stability. Furthermore, we show that the relaxation methods used for the transient analysis converge when the stability of the reluctance matrix is guaranteed. We confirm that the proposed method is 18 times faster than HSPICE and is 352 times faster than Berkeley SPICE when the full capacitance and inductance matrices are used. Moreover, when the sparse capacitance and inductance matrices are used, the proposed method is 69 times faster than HSPICE and is 1,349 times faster than Berkeley SPICE, though a small-scale problem is analyzed.