Design And Research Of A Dual-frequency Nested Base Station Antenna

Since twentieth century 70 years, the modern mobile communication technology has vigorously developed. Now the fourth generation mobile communication system is being used which is represented by LTE Advanced international standard. The base station antenna which is an important part of mobile communication system has gradualy get the trend of miniaturization, broadband and multi-system. The design of an small antenna which can be used by different systems can not only meet the current needs of the coexistence of multiple networks, but also can reduce the waste fo resource and solve the difficulty to install the antenna.According to the current trend of development, this paper design a nested dual frequency base station antenna. First, this paper introduce the development background of the mobile communication and dual band dual polarized base station antenna. Then, according to the requirements of the parameters of the base station antenna and array antenna theory, it put forward a kind of dual band antenna using nested array structure. By changing the arrangement and radiation electromagnetic boundary of high frequency array, and loading medium blocks on the top of the units, the horizontal radiation parameters of graphs are optimized. Then design the feed network for the model which has good beam width, cross polarization ratio and other indicators to get a good matching between the antenna and feeder. The feed network can help to ensure the information transmission efficiency, and opotimize the verticle radiation pattern. Finally, make the model of the antenna, measure the circuit parameters and radiation parameters and analyse the results.The result of the measurement indicate that the base station antenna has a good performance of index at 790MHz~960MHz/1710MHz~2690MHz. It can be used in 2G, 3G, LTE and other systems to make the multiple band cover come true. What’s more, because of the miniaturization of the low frequency antenna element, the whole array can not only meet the requirements of the radiation index but also can reduce the volume of the model. It has made a practical application value in LTE communication system.