Gain enhancement of a multilayer microstrip patch antenna by means of a truncated planar periodic structure

In this paper we have investigated the gain enhancement mechanism produced by the introduction of a truncated periodic structure, in a multilayer configuration, in the substrate of a the patch. We analyse the characteristics of the antenna design related to the coupling of energy between the patch and the metallic elements of the periodic structure, which are embedded in a high permittivity layer surrounding the antenna. By adjusting their size and geometry it is possible to control the electromagnetic fields in the close region of the patch, providing an increase on the impedance bandwidth and a higher radiation gain.