Microwave Landing System Azimuth Taiwan And Feeding System Design

Microwave Landing System (MLS) is an air-derived guidance system which used the time reference scanning beam (TRSB) technique to lead the plane land safely. TRSB is used in the ground facility of this landing system which can provide azimuth and elevation angle position information to the plane.The azimuth station antenna of Microwave Landing System is a separable-planar array, first this paper analyzed the radiation field of planar array and the directivity of an antenna .Based on the technical requirements of the azimuth station antenna, analysis the system and determine the azimuth of antenna is fed by Taylor distribution, the space and the number of elements are identified. The elevation radiators should meet the special requirements, the paper used the DFP-BFGS methods to optimize the result , the appropriate amplitude and phase distribution are selected, while identifying the elements space. The array is steered through the AZ coverage sector of±40 degrees, So analysis the impact of the scanning pattern is very necessary. In practical application the antenna pattern will change in many different reasons, the paper focuses on virtual displacement technology, error and the mutual coupling effects is analyzed.The characteristics of the antenna radiation element with power divider network integration to meet the request of the design is considered in this paper, select the appropriate dipole form from several different dipole models. In this paper, the power divider network is based on the stripline structure, from the theory of Wilkinson dividers. With the help of Ansoft HFSS and Designer software, power divider network and dipole model are simulated, as the result of the simulation is satisfied, Autocad drawing processing is derived.According to the measured results, each part of the azimuth station antenna have a low VSWR, despite the side lobe level of the radiation pattern elevated in the edge frequent and wide-angle scanning, In fact, the project can be used and its size has met the mobile microwave landing system's requirements.