Enhancement of Isolation and Scanning Performances of Dipole Arrays Using Decoupling Ground Technique

The decoupling ground technique is applied to a 1×4 dipole array. The isolation between each array element is improved by optimizing the decoupling ground to make the free-space coupling wave and the surface current (introduced by the ground plane) out of phase. The mutual coupling can be reduced below -25 dB with improved radiation patterns and larger scanning gains. It is also shown that grating lobe reduction can be achieved by reducing the inter-element spacing of the array.