Research And Design Of RF Receiving Front End For Interference Detection And Location Equipmen

When the satellite navigation signal reaches the ground,the intensity is very weak,and it is easily interfered by other electromagnetic waves,so that the ground receiver cannot effectively receive the useful signal,resulting in the inability to locate correctly.Therefore,this thesis will carry out the development of the radio frequency receiving front end for satellite navigation interference detection and positioning equipment,receiving and detecting radiated interference signals in a complex electromagnetic environment,and providing favorable conditions for troubleshooting and eliminating interference sources.Focusing on the research on the realization of the front-end hardware of the equipment receiving,the equipment prototype development and performance test have been completed.The main contents are as follows:The first part mainly introduces the research background of the subject,interferometer direction finding technology,antenna broadband and miniaturization technology,and interference source location technology related to the subject.In the second part,the common interference signal types are sorted out and introduced by classification;secondly,the composition and working principle of the whole equipment are introduced;then the principle of direction finding of the interferometer is explained,and the layout design of the five-element uniform circular interferometer is proposed and realized360°omnidirectional coverage,to solve the problems of the direction finding accuracy of one-dimensional linear array being greatly affected by the direction of the incoming wave,and the direction finding range is small;finally,the three-distance cross positioning method and the triangular cross positioning method are compared,and the hardware is less difficult to achieve,and the clock Triangular intersection positioning method with low synchronization requirements and suitable for various bandwidth systems.In the third part,an ultra-wideband miniaturized co-aperture antenna is designed.First,a broadband miniaturized DF antenna unit is designed based on a single cone antenna.By replacing the original large floor with concentric cylindrical blocks and loading parasitic metal pillars,the miniaturized and compact design of the cone monopole antenna is realized.The antenna size is0.167λ₀×0.267λ₀,Whereλ₀ is the maximum operating wavelength,and its size is reduced to 32%of the traditional single cone antenna.Aiming at the main navigation signal frequency band,a navigation receiving antenna covering multiple commonly used navigation frequency bands is designed.Based on the four-arm spiral antenna model,the impedance matching efficiency is improved by adding parasitic strips and the design of a broadband feed network to broaden the impedance matching bandwidth.,The antenna bandwidth can reach 46.3%.In the fourth part,an ultra-wideband reconfigurable radio frequency receiver module for satellite navigation interference detection and positioning equipment is designed.The filter can be selected through a switch to complete the signal monitoring of the entire frequency band of 1GHz～3GHz or a specific frequency band.Perform device selection and link budget based on performance indicators,and complete the hardware implementation and performance test of the radio frequency module.In the fifth part,the system prototype was developed and the performance index was verified.The device can monitor interference signals in the frequency range of 1GHz～3GHz,and its direction finding accuracy can reach 2.2°,and the interference source location accuracy is 2.75%...