基于多径效应考虑的微波着陆系统天线设计方法

为实现最大程度地降低场地环境的多径误差影响,提出了一种MLS(Microwave landingsystem)角度引导天线设计方法.该方法在深入研究场地环境多径误差的基础上,通过定义多径误差因子,给出了引起的测角误差的三方面因素:多径与直达信号电压比、天线波束宽度及多径信号微分偏移量,建立了多径测角误差与天线参数波束宽度和旁瓣电平的关系.以特定环境的MLS方位天线设计为例,给出了保证天线性能的条件下天线孔径尺寸、旁瓣电平和多径误差之间的确定性平衡关系,为MLS设计人员考虑多径误差情况下判定天线参数提供了一种有效的途径.

Antenna design of microwave landing system based on the consideration of the multi-path effects

In order to furthest reduce the multi-path error caused by siting environment, the new designed methods for the angle guidance antennas of MLS are proposed. It is based on the deep investigation in the principles of the multi-path error. Then, through the definition of multi-path error factors, the three elements related to the multipath error is presented. There are indirect/direct signal ratio, antenna aperture beamwidth and the derivative of the indirect signal. Moreover, the relationship of multi-path error to antenna beamwidth and sidelobe is built. The method is used to the MLS azimuth antenna design in an special conditions. The antenna aperture size and sidelobe are determined so that the antenna performance can is achieved. The tradeoff relationship of aperture size against sidelobe level is given an same time. It is point out that there is a certain value for antenna designers to specify the antenna parameter under the consideration of the multi-path error.