Coupling enhancement for modified double rhombus antenna array

The rhombus shape double dipole antenna is presented for wireless communications and phased arrays applications with an ultra wideband of more than 100% and stable endfire radiation patterns. A modified array configuration is constructed to improve the radiation characteristics and pattern stability of the array. The surface current is studied and techniques are applied to reduce the coupling between array elements. The final array design has an extended tapered conductor connected to the ground plane to increase the path of the current flowing from the antenna to its neighboring one. In addition, a V-shape longitudinal cut and a rectangular gap are introduced in the substrate to reduce the coupling due to the field traveling in the traverse direction.