The Body-of-Revolution Hybrid Implicit–Explicit Finite-Difference Time-Domain Method With Large Time Step Size

A novel body-of-revolution finite-difference time-domain method (BOR-FDTD) based on the hybrid implicit–explicit (HIE) difference is presented in this paper. The time step in this method is independent of mode number $m$. It is only determined by the spatial increments $\Delta r$ and $\Delta z$. Compared with the conventional BOR-FDTD method, this novel BOR-FDTD method has larger time step size, especially when the value of $m$ is large. This novel BOR-FDTD method does not require the solution of tridiagonal matrices, and all the updates in this method are explicit. The stability condition of the proposed BOR-FDTD method is presented analytically, and the numerical performance is demonstrated through numerical examples.