一款基于近场谐振技术的小型化北斗天线设计  

A miniaturized BeiDou antenna design based on near-field resonance technology

作　　者：肖天灵 陈星[1] Xiao Tianling;Chen Xing(School of Electronic and Information Engineering,Sichuan University,Chengdu Sichuan,610064)

机构地区：[1]四川大学电子信息学院,四川成都610064

出　　处：《电子测试》2022年第7期52-55,共4页Electronic Test

摘　　要：针对北斗三代导航卫星系统的工程应用,设计出了一款电小、宽带、圆极化、高效率的北斗天线。该天线设计基于近场谐振寄生(near-field resonant parasitic,NFRP)技术,其中单馈交叉偶极子作为驱动元件,一对正交放置的埃及斧偶极振子作为近场谐振寄生元件位于交叉偶极子的近场,在整个天线系统中既充当反射器实现定向辐射,又产生额外的谐振和最小轴比点以增加阻抗带宽与轴比带宽,两种元件均采用曲折线和箭头末端两种技术,以实现电小形式。此外,位于驱动元件附近的4个T型谐振结构用于进一步改善天线的性能。设计和加工制作了天线样品并进行了测试。测试表明,作为电小天线,天线整体尺寸为34mm×34mm×13.4mm(为1.49GHz对应波长),其|S11|<-10dB的阻抗带宽为1.49-1.87GHz(相对带宽22.6%),3dB轴比带宽为1.52-1.69GHz(相对带宽10.6%),两者均覆盖了北斗三号B1I(中心频率1.561GHz,绝对带宽4.092MHz)与B1C(中心频率1.575GHz,绝对带宽32.736MHz)两个工作频段;在这两个频段内,天线整体辐射方向均为天线法线方向,辐射效率均超过80%。Aiming at the engineering application of BeiDou’s third-generation Navigation Satellite Systems,a broadband electrically small circularly polarized BeiDou antenna with high efficiency was designed.The antenna design is based on near-field resonant parasitic(NFRP)technology,in which a single-fed crossed dipole is used as the driving element,and a pair of orthogonally placed Egyptian axe dipoles are located in the crossed pair as the near-field resonant parasitic element,the NFRP not only acts as a reflector in the entire antenna system to achieve directional radiation,but also generates extra resonances and minimum axial ratio(AR)points to increase the impedance bandwidth and axial ratio bandwidth.Both elements adopt two technologies:meander line sections and arrow-shaped ends to realize the electrically small antenna.In addition,four T-shaped resonant structures located near the driving element are used to further improve the performance of the antenna.An antenna prototype is designed,fabricated and tested.The test result show that,as an electrically small antenna,the overall size of the antenna is only 34mm×34mm×13.4mm(whereλ0 is the working wavelength at 1.490GHz),the impedance bandwidth for|S11|<-10dB is 1.49-1.87GHz(relative bandwidth 22.6%),and the 3dB axial ratio bandwidth is 1.52-1.69GHz(relative bandwidth 10.6%),both of which cover B1I(which working center frequency is 1.561GHz,and absolute bandwidth is 4.092MHz)and B1C(which working center frequency is 1.575GHz,and absolute bandwidth is 32.736MHZ)band of BeiDou’s third-generation Navigation Satellite Systems;the antenna The overall radiation direction is the normal direction of the antenna,and the radiation efficiency exceeds 80%in B1I and B1C band.

关 键 词：北斗天线 圆极化 电小 宽带 近场谐振寄生 

分 类 号：TN828.5[电子电信—信息与通信工程]