Research On Broadband Base Station Antenna

The base station antenna is widely used equipment in mobile communication.There are many types of research on base station antenna,including all aspects of base station antenna design.At present,the basic characteristics of the applied base station antenna are multifrequency,dual-polarization,intelligence,and array.However,mobile communication is still developing,and the demand for channel capacity is still increasing.The most popular way to improve channel capacity is to expand communication frequency bandwidth.Therefore,in the research of base station antenna,expanding the working bandwidth of base station antenna has always been the main research direction.Compared with a single-port feed base station antenna,the differential feed has other advantages.For example,if the balun is not needed,the feed structure is simple,the common-mode rejection characteristic is good,and the radiation pattern is symmetrical.In the research process of this paper,it is found that the differential feed base station antenna has the above advantages and plays an important role in expanding the working bandwidth of the base station antenna.Based on this discovery,this paper makes detailed research on the differential feed base station antenna and designs three differential base station antennas using this feature.In the first antenna,a method of nesting metal tubes for feeding coaxial lines is designed to stabilize the impedance matching changes caused by different coaxial lines.The second antenna uses the third resonance mode brought by differential feeding and designs a base station antenna with a relative bandwidth of 82%.The third one uses the stacked technology of nested metal tubes and dipoles simultaneously and skillfully uses the advantages of differential feeding to design a base station antenna with novel structure and exploratory significance,and its relative bandwidth can reach 115%.The miniaturization of the base station antenna is also an important re-search direction.Simple miniaturization is not very difficult,but it is difficult to maintain the same relative bandwidth of antenna based on miniaturization.At the same time,this paper studies the low profile of the shared dipole antenna and designs a base station antenna whose height is only 0.1times the wavelength of the center frequency.At the same time,the indoor base station antenna is also an important part of mobile communication.Compared with the common base station antenna,the antenna used indoors may not require much pattern and gain,but there is no difference in other aspects.Of course,due to different applications,the design method of an indoor base station antenna is quite different from that of a common base station antenna.However,the research on in-door base station antenna mainly focuses on broadband,which is consistent with the base station antenna and is caused by the frequency expansion of mobile communication applications.At the same time,based on the research on two folded dipoles,this paper designs a dual-band broadband indoor antenna with a relative bandwidth of 63% and 41%,respectively.