Alternative approaches for minimizing surface wave effects on phased array antennas

A dielectric sheet in contact with the radiating structure of a phased array gives rise to scan volume limited by blind spots arising in phase synchronization of one of the Floquet modes with a guided surface wave. Different ways can be utilized to reduce the effects of surface wave propagation such as introducing a gap between the dielectric (cover) and the planar/conformal antenna, appropriate reactive loading of the surface of the antenna, or the inclusion of a high Z surface either on the surface or on the ground plane. These different methods are analyzed and compared for convenient optimum utilization.