COMPARATIVE STUDY ON DIFFERENT HIS AS GROUND PLANES AND ITS APPLICATION TO LOW PROFILE WIRE ANTENNAS DESIGN

In this paper, the characteristics of three different types of high impedance surfaces (HIS) to be used as ground planes for low profile wire antennas are investigated and compared: a mushroom-like surface, which is the classical example of HIS with connecting vias, and two surfaces with no vias, one of which is anisotropic. Both the simulation results and the measurements verify that the high impedance behaviour is successfully accomplished around the resonant frequency. In order to complete the study, return loss and radiation pattern of a horizontal dipole placed above the surfaces are analyzed.