Analysis of obliquely launched plane wave steering using electromagnetic band gap (EBG)

By arranging electrical gradient surface of which reflection phase is dependent on surface impedance Z_s of EBG, beam steering has been realized. But because this surface impedance (Z_s) strongly depends on the angle of incidence (θ_i) of a plane wave, furthermore, the angular dependence of the surface impedance (Z_s) is different for TE and TM polarized waves, the angle of reflection cannot be calculated acutely in EGS surface when plane wave is excited obliquely. By considering the reflection phase corresponding incident angle & polarization, reflection angle can be controlled by adjusting the gradient of reflection phase across the surfaces. Using theoretical calculations and FEM simulations, it was shown that even though source wave are launched obliquely, the reflected angle was accurately calculated.