Discrete Green´s function formulation of the FDTD method and its application in antenna modeling

A discrete Green´s function formulation of the finite-difference time-domain (DGF-FDTD) method based on both discrete system theory and the FDTD method has been developed, which expresses the field response as a convolution of current sources and the impulse response of the FDTD equation system. The DGF-FDTD method presents the FDTD equations in a different perspective from the conventional Yee algorithm. It avoids the computational difficulties such as the need for computation of free-space nodes and absorbing boundary conditions of the classic FDTD method. The ability of the DGF-FDTD method to model on antenna is demonstrated by the modeling of a Yagi-Uda array antenna with considerable saving in memory usage.