Research And Implementation Of Single-pulse Single-channel Angle Tracking Receiver

This thesis is based on the mission requirements of a line-of-sight UAV communication equipment.The communication system works on the C-band.In order to improve the communication distance,there used a directional antenna with narrow beam width for the ground receiver,so the ground equipment needs to automatically track the UAV.Now,the major way about automatic tracking methods include sequential lobing,conical scanning and monopulse tracking technology.The sequential lobing and the monopulse tracking technology belong to the equisignal system,and the conical scanning belongs to the maximum signal method.In addition,monopulse tracking technology is the most common tracking method because it has the highest tracking accuracy and the shortest response time.In this article,I studied the development of radio tracking technology both at home and abroad.Starting with the monopulse tracking technology,it analyzes the advantages and disadvantages of the amplitude comparison monopulse,phase comparison monopulse and sum difference monopulse,and focuses on the principle and Angle tracking flow of the singlechannel monopulse Angle tracking receiver.Firstly,Firstly,I designed the front-end circuit of the single-channel Angle tracking receiver,and the scheme of amplification + filtering +amplification + filtering is adopted to suppress the transmitted signal as much as possible and optimize the noise COEfficient under the premise of ensuring the unsaturation of all levels of devices.Secondly,the baseband signal processing algorithm of single-channel Angle tracking receiver is studied,including bandpass sampling,digital down conversion,demodulation and Angle error signal extraction,and the azimuth difference and pitch difference signal extraction is realized based on FPGA,and the feasibility is verified by simulation.The cross-coupling calibration of azimuth and pitch Angle due to phase inconsistency of sum and difference channels before single channel synthesis is studied,and the phase difference of RF channel and difference channel is compensated by digital method.The method of sequential sampling by low frequency square wave is adopted to extract the azimuth Angle and pitch Angle.Finally,the hardware system of the monopulse single-channel angle-tracking receiver is realized,and the tracking performance of the designed monopulse single-channel angle-tracking receiver is verified by laboratory simulation and field tests.The final test results show that the scheme is correct and practical.In this paper,the overall scheme of the monopulse single-channel Angle tracking receiver is designed,and the hardware circuit and software programming of the monopulse singlechannel Angle tracking receiver are completed.The system designed can be applied to the fields of unmanned aerial vehicle,satellite measurement and control,etc.