多模卫星定位导航系统的宽带天线

为解决单一系统覆盖空白和定位精度低的问题,提出一种多模卫星定位导航系统终端的宽频带圆极化微带天线.通过选用低介电常数泡沫材料组成叠层微带天线结构,采用宽带功分相移网络和倒L带条近耦合四臂平衡馈电,充分展宽了天线的阻抗带宽和圆极化带宽.功分相移网络采用带状线四周封闭结构,抑制了馈电网络寄生辐射对天线方向性的影响.给出了天线的设计思路,分析了结构参数对天线性能的影响.仿真结果表明:天线具有较好的特性,驻波比<1.5的阻抗带宽达48%,轴比<3 dB的圆极化带宽达67%.对天线进行了加工测试,测试结果与仿真结果具有较好的一致性,并且在工作频带内天线增益高于6 dB.设计的天线能满足接收多模导航卫星信号的要求,具有良好的应用前景.

Wide-band terminal antenna for multi-mode satellite navigation

A wide-band circularly polarized microstrip antenna is proposed for multi-mode satellite navigation terminals.It comprises a stacked microstrip antenna with low permittivity material of foam and a broadband power-divider phase-shifter network.Utilizing the proximity coupling balance-feed with four-arm inverted L-strip,the impedance bandwidth and circularly polarized bandwidth can be effectively enhanced.The feed network adopts strip-line with closed structure to suppress the influence of network parasitic radiation on the antenna directivity.The antenna design scheme is presented and the design parameters are analyzed.The simulated results show that the impedance bandwidth is up to 48% for vswr<1.5,and the circularly polarized 3 dB axial-ratio bandwidth is up to 67%.The antenna was fabricated and measured.The measured results have a good agreement with simulated results,and its antenna gain is better than 6 dB during the whole work band.The designed antenna can receive the signals of multi-mode satellite navigation systems and is promising in application.