Dual-grid finite-difference time-domain scheme for the fast simulation of surrounded antennas

A new finite-difference time-domain (FDTD) multiresolution strategy for surrounded antenna analysis is presented. The dual-grid FDTD (DG-FDTD) is divided into two FDTD simulations using different grids. Indeed, the antenna is firstly simulated without its environment using a finely discretised FDTD in order to determine its main characteristics and save its primary radiation. In a second step, this saved field is used as the excitation of a coarse FDTD to simulate the antenna with its environment. The application of the DG-FDTD to an ultra wide-band problem is discussed, and the DG-FDTD turns out to be an accurate and fast tool to simulate various antenna configurations. Furthermore, this method remains stable along the computational time, and is easy to implement in a classical FDTD scheme