双频航向信标水平辐射特性的实现

Realization of dual-frequency localizer horizontal radiation characteristics

目前,民用航空的精密进近服务几乎由仪表着陆系统(ILS)支持,其提供水平引导信息的航向信标(LOC)水平辐射特性直接影响ILS的导航性能。利用三维电磁仿真软件FEKO,设计了目前LOC广泛使用的由7个对称振子组成的双层结构的对数周期偶极子天线(LPDA),在此基础上,结合双频LOC馈电方式,仿真实现了双频12单元LOC的辐射方向性图。结果表明:所设计的LPDA基本符合LOC阵元半功率波瓣宽度的要求,LOC阵列天线的水平辐射特性满足ICAO相关标准的覆盖要求。

ILS provides precision approach service for civil aviation.The horizontal radiation characteristics of LOC that provides horizontal guidance information directly affects the navigation performance of ILS.Using 3D electromagnetic simulation software FEKO,an LPDA composed of seven symmetric oscillators which is widely used in LOC,is designed.Combined with dual-frequency LOC feeding mode,the radiation pattern of dual-frequency 12-cell LOC is realized through simulation.Results show that the designed LPDA basically meets the HPBW requirements of LOC array element,and the horizontal radiation characteristics of LOC array antenna meet the coverage requirements of the relevant standards of ICAO.