Quadrature Hybrid Integrated Dual-Circularly Polarized Array Antenna

A new dual-circularly polarized array antenna integrated with a quadrature hybrid is presented in this paper. The antenna shows wideband performance due to the wideband characteristic of the quadrature hybrid. Two substrate layers and three metal layers are used to realize the proposed antenna. Bothsided MIC technology is used to distribute the whole feed network on the different substrate layers. Use of this technique leads to compact structure of the proposed array antenna. Two orthogonal modes with quadrature phase shift to excite circular polarization is achieved by using orthogonally fed patches and quadrature hybrid. Moreover, use of quadrature hybrid enables to change the circular polarization sense. The performances of the proposed antenna is experimentally validated and measured axial ratios are more than 9{\%}.