Characteristic-based time domain method for antenna analysis

The characteristic-based time domain method, developed in the computational fluid dynamics community for solving the Euler equations, is applied to th e antenna radiation problem. Based on the principle of the characteristic-b ased algorithm, a governing equation in the cylindrical coordinate system i s formulated directly to facilitate the analysis of body-of-revolution ante nnas and also to achieve the exact Riemann problem. A finite difference sch eme with second-order accuracy in both time and space is constructed from t he eigenvalue and eigenvector analysis of the derived governing equation. R igorous boundary conditions for all the field components are formulated to improve the accuracy of the characteristic-based finite difference scheme. Numerical results demonstrate the validity and accuracy of the proposed tec hnique.