Huygens Excitation in Debye Media in the FDTD Method

The total-field/scattered-field method, also called the Huygens surface method, is a common method to enforce an incident wave in a finite-difference time domain grid filled with a vacuum. In this communication, it is shown that it can also be used in such dispersive media as the Debye media. The incident wave to be enforced on the Huygens surface is computed either by an analytical calculation in the general case or by means of the auxiliary grid technique in special cases. As in a vacuum, the leakage of energy outside the Huygens surface is lower than -40 dB with the analytical incident wave and it can be far lower with the auxiliary grid incident wave.