A novel 2-D electromagnetic band-gap structure and its application in micro-strip antenna arrays

Microstrip antenna arrays have found broad applications in recent years, while the mutual coupling between array elements can cause various degrees of degradation in their performance. Different techniques have been carried out to solve the problem such as removing part of the dielectric materials or ground plane between adjacent elements, or inserting electromagnetic band-gap (EBG) structures into the space between them (F. Yang and Y. Rahmat-Samii, IEEE AP-s Dig. vol. 2, pp. 478-481, 2001). A novel EBG structure has been developed in this paper. Using the method of moments, a simple two-element patch array with and without the EBG structure has been simulated. It has been demonstrated that the EBG structure can reduce the mutual coupling due to surface waves, and the performance of the array has been improved. Also, a comparison has been carried out between the new structure, the UC-EBG structure (R. Coccioli et al., IEEE Trans. MTT vol. 47, no. 11, 1999), and the patch-via-EBG structure (D. Sievenpiper et al, ibid., vol. 47, no. 11, 1999). The advantages of the new structure over the others have been proved.