A planar antenna array with separated feed line for higher gain and sidelobe reduction

Abstract

A new antenna structure with lower side lobe pattern and higher gain was designed by combining a microstrip rectangular planar antenna array with the separated feed network technique. In this paper, the side lobe behaviors of two different radiating structures have been studied and compared. The first antenna configuration (“Structure 1”) is a 16-element planar antenna array whose feed line is printed on the same plane as the radiating elements. The second one (“Structure 2”) is a 16-element planar antenna array whose feed network is separated from the radiating elements by an air gap. This technique enables one to reduce the unwanted spurious effects from the feed line. Both antennas are designed at 5.8 GHz. Compared to “Structure 1” we show that the optimization of “Structure 2” allows reducing the side lobe level and increasing the antenna gain. The experimental results are shown to be in very good agreement with the numerical simulations.