Research Of The Monopulse Feed On The Single Channel At S-band For Automatic Tracking

The selection of this thesis is presented with the scientific research project of 5.2 meter vehicle teleantenna,the design scheme of the monopulse feed on the single channel at S-band for automatic tracking are discussed.The research contents of this thesis can be summarized as follows:Firstly,the related concepts used in this thesis are explained,the research status and existing problems at home and abroad are discussed,expound the background and significance of the monopulse feed on the single channel at S-band for automatic tracking.Secondly,the monopulse feed on the single channel at S-band for automatic tracking is studied,the specific research work is follows:1.According to the requirement of the system for 5.2 meter vehicle teleantenna,the technical difficulties of realizing the index are analyzed,including the realization of feed double circular polarization,miniaturization,high efficiency and broadband index.The technical ways to solve the above technical difficulties are put forward.The technical scheme of the monopulse feed on the single channel at S-band for automatic tracking is determined.2.According to the design scheme,the feed radiator and feed network are simulated and designed by HFSS,and the radiation pattern of feed radiation is brought into Grasp to verify.The working frequency band of feed is 2.2GHz-2.8GHz,the irradiation level of “sum” pattern is 9d B-14 d B,and there is no sidelobe in the irradiation angle of “difference”pattern,the difference depth is more than 37.5d B,and the difference spacing of radiator is 148 mm,which is 40% smaller than that of the same type of feed radiator.The simulation results of feed network show that the operating frequency band of broadband bridge is 2.2GHz-2.8GHz,the voltage standing wave ratio is less than 1.2:1,and the phase characteristic is 90°±2°.The simulation results show that the electrical parameters of the feed fully meet the requirements of the design index,the design scheme is reasonable and feasible.3.Under the condition that the simulation design meet the requirements,the monopulse feed on the single channel at S-band for automatic tracking engineering prototype is developed,the test reasult show that the voltage standing wave ratio is less than 1.3:1 and the insertion loss than 1.03 d B.The engineering prototype is applied to the 5.2 meter vehicle teleantenna,the test reasult show that the sum efficiency of 2.3GHz is 0.6,the axial ratio is 0.77 d B,the difference depth is more than 32.08 d B,and the difference slope is more than 0.9078/dgree,the test reasult of the prototype and the antenna are in good agreement with the design results,which verifies the effectiveness of the design method,at the same time,it also shows that the developed engineering prototype fully meets the engineering requirements.Finally,the further research works about the monopulse feed on the single channel at S-band for automatic tracking are pointed out.