High gain, low radar cross-section, and left hand circularly polarized antenna array based on metamaterial inspired elements

Abstract

In this research work, a wideband metamaterial-inspired circularly polarized antenna array is designed. The designed antenna array has a low radar cross-section (RCS) but high gain. The basic element of the planar array is analyzed as a dual-band electromagnetic absorber. Under normal incidence, the designed basic element has two absorbing peaks at 3.6 and 11.2 GHz. Further, four elements of the 4 x 4 elements array are connected to the feeding network through metallic vias. The feeding network is designed on the bottom layer. The circular polarization is archived by feeding the cross shape metallic resonator at two feed points, in a manner that there is a 90 degrees time phase difference between the fields of two. It is shown that a good axial ratio is obtained over a wideband. This design method simultaneously validates high gain antenna performance and also meets the conditions of low-RCS.