Mutual coupling is an inevitable phenomenon in multielement antenna systems. It can significantly degrade the performance of array systems. A number of works have been done on the suppression of mutual coupling in the recent years. In this article, we propose a simple I‐shaped resonator in between two E‐shaped microstrip antenna elements separated by 0.45λ to reduce the mutual coupling in patch array of antennas. The mutual coupling has been reduced by more than 30 dB by the introduction of this simple I‐shaped resonator on the same plane of the microstrip radiator. We have developed an experimental model that has proven this concept of antenna coupling reduction. Finally, the influence of other antenna parameters on the mutual coupling level has been studied. One may find its application in wireless communication. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2544–2549, 2013