Design And Research Of Wideband Differential-fed Microstrip Filtering Antenna

With the rapid development of wireless communication technology,the number and complexity of RF front-end structures have increased dramatically,and multi-functional system modules with features such as miniaturization,integration,and ease of processing have received extensive attention.Antennas and filters play a vital role in wireless communication systems.The size,radiation efficiency and filtering effects of the two systems can seriously affect the operating state of the entire system.In the traditional design process,the antenna and filter are often designed separately,and then cascaded through the transmission line or other means,which will lead to a serious impedance mismatch between the two devices,and wireless communication the overall structure size of the RF front end of the system will be large,and the loss of the antenna will increase accordingly.In order to overcome these problems,the research of the filtering antenna capable of simultaneously achieving the radiation effect and the filtering performance,and the overall structure is simple,compact,and excellent in overall performance has been widely concerned.In this paper,the differential-fed technology,combined with the low cross polarization,symmetric and stable pattern characteristics of the differential-fed antenna,the broadband microstrip filtering antenna is studied.The main work content is composed of the following aspects:Firstly,the research significance of the filtering antenna and the development status at home and abroad are introduced.At the same time,the theoretical knowledge of the microstrip antenna is systematically arranged and elaborated.Combined with the 5G mobile communication frequency band,a center frequency of 4.9 GHz is designed.The wideband microstrip filtering antenna has higher gain than other antennas,and the filtering effect is also obvious.Secondly,on the basis of the previous work,a new differential-fed microstrip filtering antenna is proposed based on the differential-fed technology.Due to the differential-fed technology,the radiation pattern of the antenna is more symmetrical and the radiation pattern symmetry and cross polarization has been significantly improved.Next,considering that the dual-polarized antenna can realize polarization diversity in the communication system and increase the communication capacity,it is improved to a dual-polarized differential-fed wideband microstrip filtering antenna based on the differential filtering antenna.The antenna have the substantially same bandwidth and gain in the horizontal polarization and vertical polarization directions.At the same time,this antenna is in the form of differential-fed,which enables higher port isolation.Finally,in order to realize the high gain antenna,the microstrip filtering antenna is designed into a 1*4 array to form a new array antenna.The results show that the gain of the antenna array is improved and has good filtering characteristics.