Mutual coupling reduction of microstrip antenna array using metamaterial absorber

In this paper we describe a novel approach to reduce the mutual coupling in microstrip antenna arrays by using metamaterial absorber (MA). The MA is constructed with split-ring resonators to suppress the surface current propagation between two microstrip antenna elements at the resonant frequency. By inserting the MA, it has been achieved an improvement in decoupling by 10.8 dB with a center-to-center spacing of 30 mm at 5.1GHz. This scheme is capable of not only providing good decoupling level for closely-spaced microstrip antennas but also advancing a step further in achieving low in-band radar cross section(RCS) of antenna array.