Study of decoupling between patch elements of microstrip array using electromagnetic soft surface

Abstract

Electromagnetic coupling is one of the important and necessary issues for the design of antenna arrays. Mutual coupling degrades array performances like antenna gain, radiation pattern, antenna efficiency etc. In this paper, the authors have put forward a novel technique for reduction of mutual coupling between microstrip patch elements. A 4-element antenna array loaded with electromagnetic soft surfaces (EMSS) has been designed to achieve considerable suppression of mutual coupling between two adjacent patch elements. The EMSS are designed using metal strips loaded with reverse C-shaped slots. With the introduction of two EMSS unit cells between patch elements, a noticeable reduction in mutual coupling between patch elements is achieved without degradation in other performances of the array. The experimental results presented are compared with the simulated ones and it is observed that the proposed EMSS loaded array structures cause excellent suppression of electromagnetic coupling with a reduction of about 35 dB at the designed frequency of 3.65 GHz.