Reducing Mutual Coupling of Millimeter Wave Array Antennas by Fractal Defected Ground Structure

A high isolation, high gain and compact patch antenna arrays that operates in 11.4–11.78 GHz by using fractal defected ground structure (Fractal-DGS) is designed. Performance of the antenna arrays, such as isolation and radiation, are simulated and compared with conventional patch antenna array without Fractal-DGS. As is presented in this paper, the mutual coupling is −33dB at working frequency, it reduces 13dB compared with the traditional antenna array. And the radiation direction is better than conventional antennas too. Higher isolation and stable directional radiation pattern make this antenna array a better choice for millimeter wave communication system.