FDTD analysis of an antenna covered by a dielectric woodpile EBG superstrate

In this paper we study the antenna/woodpile electronic bandgap (EBG) composite by using the finite difference time domain (FDTD) Method. The near-field as well as far-field performance are examined at different frequencies with a view to realizing enhanced directivity. In addition, the structure is modeled and simulated under plane wave illumination and the scattered fields are computed to gain an understanding of the mechanism of directivity enhancement. Furthermore, a periodic FDTD code is used to model a unit-cell of woodpile to show that the angular response has a sharp drop as we move away from the zenith, which is closely associated to the directivity enhancement at the resonant frequency.