Microstrip gap proximity fed-patch antennas, analysis, and design

In this paper, a new feeding structure is applied in the patch antenna design to overcome undesirable features of the earlier multilayer feeding structures while maintaining their interesting features. To more readily understand the operation mechanism of proposed feeding structure, an efficient circuit model including the gapped strip-line feed mechanism has been also presented. It is known that proximity and aperture coupled feeding structures are sensitive to the transverse feed point location. In contrast, the proposed feeding architecture is very easy to fabricate and it overcomes the alignment difficulties arising from the proximity and aperture coupled feeding structures. In other words, the input matches of the antennas with different transverse feed point locations are significantly improved at the frequencies close to the antenna resonant frequency as compared to the conventional proximity-coupled patch antennas. The CST simulation results, analytic results and measurement ones show good agreement with each other.