Electronic International Standard Serial Number (EISSN)
1558-2221
abstract
Periodic structures can help in the reduction of mutual coupling by using their capability of suppressing surfacewaves propagation in a given frequency range. The purpose of this work is to show the viability of using a planar electromagnetic band gap (EBG) structure based on a truncated frequency selective surface (FSS) grounded slab to this aim. The goal is to use it in patch antenna arrays, keeping both the element separation smaller than 0 for grating lobes avoidance (assuming broadside case) and the patch antenna size large enough to have a good antenna directivity.To this aim, a multilayer dielectric substrate composed of high and lowpermittivity layers is convenient. This allows the use of a planar EBG structure made of small elements printed on the high permittivity material and, at the same time, the low permittivity layer helps the bandwidth and the directivity of the antenna to be increased. The EBG structure was designed under these premises and optimized for the particular application via an external optimization algorithmbased on evolutionary computation: ant colony optimization (ACO). Themutual coupling reduction has beenmeasured and it is larger than 10 dB with a completely planar structure.