Bowtie-shaped DGS for reducing coupling between elements of planar array antenna

In this paper, the utilization of bowtie-shaped defected ground structure (DGS) incorporated into the groundplane of planar array antenna is proposed to reduce the coupling between two elements of planar array antenna. A double side of FR4 epoxy dielectric substrate with the dimension of 105mm × 130mm and the thickness of 1.6mm is used to deploy the planar array antenna. Two elements of planar array antenna are placed on the top side of dielectric substrate, while the bowtie-shaped DGS is put in the groundplane at the bottom side. To reduce the amount of coupling between two elements of planar array antenna, the DGS which takes bowtie-shaped is introduced. From the results, both simulation and measurement verified that the bowtie-shaped DGS reduced the coupling at the resonance frequency of 1.955 GHz. The simulated and measured couplings could be reduced up to 0.67 dB and 2.4 dB, respectively.