Reducing the mutual-coupling between the elements of a printed dipole array using planar EBG structures

Printed elements of a phased array antenna can often suffer from significant mutual coupling between them due to the excitation of surface waves. In this paper, an array of two identical printed dipoles operating at 4.2 GHz along with a planar EBG inserted between the array elements has been designed, fabricated and tested. Computed and measured results show that as much as 13 dB reduction in mutual coupling can be achieved. Insertion of the planar EBG also improves the return loss and gain.