双层空气型高性能精确导航天线设计

Design of a Double-layer Air-type High-performance Precise Navigation Antenna

基于层叠式结构,设计了一款双频全球卫星导航系统(Global Navigation Satellite System,GNSS)贴片天线。天线采用空气介质、层叠式圆形辐射片结构,实现双频带、低轴比、高增益的性能。双层辐射片共用一组馈针进行耦合馈电,能够减少一半馈针,有效简化了馈电网络的复杂性,同时保证了良好的圆极化性能。引入的4个馈电电容片可以抵消长馈针引入的电感,从而扩大工作带宽。而且对称的四馈针馈电技术和宽带相移网络的应用保证了天线相位中心稳定性。实测结果表明,该天线S 11<-10 dB的频带范围为980~1920 MHz(带宽940 MHz),增益大于3 dBic的频带范围为1106~1304 MHz(带宽198 MHz)、1420~1986 MHz(带宽566 MHz),而轴比在以上频带范围内均小于3 dB。实测频谱显示,该天线工作频段覆盖目前在运行的四大导航系统的工作频点,满足GNSS精确测量与定位系统终端设备应用需求。

Based on the stacked structure,a dual-band global navigation satellite system(GNSS)patch antenna is presented.The antenna adopts stacked circular radiation plates with air medium to realize dual-band,low axial-ratio and high-gain performance.The two radiation plates are excited by coupled feeding with a set of feeding pins,which reduces the feeding pins by half,resulting in simplifying the feeding network,while ensuring good circular polarization performance.The introduction of four feeding capacitors can offset the inductance which is introduced by the long feeding pins,thereby broadening the bandwidth of the antenna.Moreover,the phase center stability is guaranteed due to the application of four symmetrical feeding pins and the broadband phase-shift network.The measured results show that the frequency band range(S 11<-10 dB)is 980~1920 MHz(bandwidth 940 MHz),the frequency bands of gain greater than 3 dBic are 1106~1304 MHz(bandwidth 198 MHz)and 1420~1986 MHz(bandwidth 566 MHz),and the axial ratio is less than 3 dB in above frequency bands.The measured spectrum shows that the developed antenna can cover all corresponding operating bandwidth for GNSS and meets the application requirement of GNSS precision measurement and positioning system terminal equipment.