Mutual coupling investigation of two wideband dipole antennas on EBG ground plane

Nowadays, using EBG as antenna ground plane is well known in the antenna community. But most applications are limited to narrowband antennas. A broadband antenna mounted on an EBG structure has been investigated recently in the University of Birmingham. It performs well over 4.8 to 6.8 GHz with return loss lower than -10 dB, gain greater than 6 dB and good radiation pattern. In this paper, this research has been carried on. Two broadband diamond dipole antennas are mounted above the same EBG structure in H-plane and E-plane directions with different distances between them. The variation of mutual coupling (S21) between two dipoles caused by distance change and EBG structure utilization is investigated over 4 to 13 GHz frequency range and mutual coupling comparisons between antennas with and without EBG structure has been performed over 4.8 to 6.8 GHz frequency range.