Mutual coupling reduction of microstrip patch antenna array using modified split ring resonator metamaterial structures

In this paper, we present a new method to reduce the mutual coupling of a microstrip patch antenna array by using modified split ring resonator (MSRR) metamaterial structures. The designed MSRR unit-cell consists of two nested rings, and each ring has two symmetrical splits. The original microstrip patch antenna is operated at 5.3 GHz, and edge-to-edge distance between the original antenna elements is 21.5 mm which is about 0.38λ0. By placing MSRR metamaterial structures to the both sides of the antenna array, the isolation of the antenna array is greatly enhanced. The simulation results show that the isolation is reduced more than 23 dB without affecting the operating frequency and radiation characteristics.