The Design Of Array Antenna For DME/P

Since the Microwave Landing System(MLS) was introduced as the substitute for the Instrument Landing System(ILS) in the 1970 s,the MLS has been used widely and developed rapidly because of its excellent accuracy of measurement and good ability in anti-interference. Precision Distance Measure Equipment(DME/P),as an important part of the Microwave Landing System, plays a significant role in affording accurate distance information for every approaching aircraft. Antenna, as an indispensible equipment in Precision Distance Measure Equipment, its performance will directly affect the test precision of the whole system and determine whether the aircraft lands safely. This paper uses the slot coupled microstrip antenna as radiation unite to design a low side-lobe array antenna for DME/P. The antenna element and array are simulated and analyzed with the help of HFSS, a kind of electromagnetic simulation software. This paper includes following several aspects of the work:1.The scheme of array antenna is discussed and analyzed according t o the given requirements of design indicators for the DME/P antenna array. Then, H type slot coupled microstrip antenna is selected as the radiation element of the array antenna, the feed amplitude and feed phase of each unit of the DME/P array antenna are given using the Taylor synthesis method and array antenna pattern synthesis. The size of antenna unit is given out by parameter sweep analysis, then an ideal feeded 8 element DME/P array antenna is designed by using the H type slot coupled microstrip antenna as the units and the simulation analysis about this array antenna is carried out, the simulation results show that the ideal feeded DME/P antenna array meets technical requirements in entire operating band, thus the validity of unit selection, array structure, feed amplitude and feed phase is verified.2.In accordance with the feed amplitude and feed phase obtained by Taylor synthesis, the feed network for DME/P array antenna is designed by taking advantage of Wilkinson power divider, then the feed netwok is simulated and analyzed.The simulation results of amplitude and phase difference of per output port are given, and satisfy design requirements of the feed network.3.Afterwards,the designed feed network is connected with the H type slot coupled microstrip antenna in the ideal feeded DME/P array antenna, then, the overall structure of the array antenna is simulated and analyzed using HFSS and the final results are given.4.According to simulation model the antenna is fabricated, then the standing wa ve and radiation pattern is measured in anechoic chamber. The measured results are in good agreement with the simulation results, satisfied the demand of antenna array for DME/P.At last, the full text is summarized, the deficiencies in this paper are pointed out and the direction for the next step of work is also indicated.