| Dual-polarized antenna technology is one of the key technologies of wireless communication technology,and its technology can make the antenna receive and transmit work simultaneously,which can enhance the quality and reliability of the wireless link and reduce the multipath fading.In the signal transmission process of multiple channels,due to the electromagnetic field generated by the channel itself and the external electromagnetic field,it will make the antenna interfered in the working process and make the strong electromagnetic coupling between different channels.Therefore,the suppression of electromagnetic interference during the transmission of signals in the channel is an important issue.In this thesis,we will focus on the research of dual polarization antenna with high isolation,and the main work includes the following three aspects:1.A dual-polarized antenna with low cross-polarization and high isolation based on a Y shaped structure is designed.The antenna consists of a rectangular radiating patch and two orthogonal feed networks.Excitation of orthogonal polarization pattern by orthogonal feed,isolation between ports can be improved,and the Y shaped structure can make the current distribution on the patch more uniform and symmetrical and reduce the cross-polarization.The interference suppression between port 1 and port 2 is greater than 45 d B,and the cross-polarization suppression is 23 d B.2.A dual-polarized antenna is designed for WLAN(2.4 GHz-2.48 GHz)applications.The antenna consists of hairpin resonators and a radiating patch to form a second-order filter antenna to broaden the bandwidth.H-shaped slots are embedded in the ground plane,the coupling current between the antenna ports are reduced and the isolation of the two ports are improved.In the antenna operating band,the isolation between the two ports of the antenna is better than 38 d B,and the cross-polarization of the E-plane and H-plane of the antenna is below-28 d B.3.A broadband dual-polarized antenna with low cross-polarization base on multimode resonance is designed.The operating band of port 1 covers1.54 GHz-4.85 GHz and that of port 2 covers 1.93 GHz-4.85 GHz.The antenna consists of a monopole and a rectangular slot ring,which can achieve broadband by excitation multiple resonant modes of the monopole and slot ring in both x-directions and y-directions.By adding U-shaped branches on the annular radiantion element,the cross-polarization at the high frequency resonance point can be improved. |
