Design Of A Compact Multimode Anti-interference Antenna

With the gradual improvement of China's satellite system,satellite resources are becoming more and more abundant.The multimode satellite antenna which can effectively use a variety of satellite systems has become a research hotspot.The power of the satellite signal received at the receiver is very low and is very vulnerable to various interferences in the environment.Therefore,it is particularly important to study the satellite anti-interference technology to ensure that the receiver can correctly capture the satellite signal.Thesis designs a compact multimode anti-jamming antenna,including the design of compact multimode antenna and the hardware implementation of anti-jamming algorithm.The thesis'research substance is divided into two sections:The first part is the design of compact multimode antenna.Firstly,beginning with the fundamental principles of microstrip antennas,the theory of circular polarization and miniaturization of microstrip antennas is presented.Three satellite circular polarization antennas are designed by using satellite terminal antenna as the technical application backdrop.Among them,the size of the dual band laminated circular polarization antenna covering B2b and L band is reduced to0.216?₀×0.216?₀×0.06?₀ by means of high dielectric constant and patch loading C-shaped slot,and the port isolation is less than-20d B;a multilayer resonant structure antenna covering the S1 band is capable of achieving a relative bandwidth of 15%.On the basis of the three designed antenna units,a research on compact multi-mode antenna array has been carried out.By loading the metallized perforations in the feed network layer can effectively reduce the mutual coupling problem of antennas in the array,and the processing measurement shows that the antenna array meets the design requirements.The second part is the research and engineering implementation of adaptive anti-interference algorithms.The thesis firstly introduces the adaptive filter optimality criterion and its application environment,as the interference signal power is much larger than the satellite signal,it is suitable to use power inversion algorithm for anti-interference processing,and simulates and compares the Least Mean Square(LMS)algorithm and Recursive Least Square(RLS)algorithm that are based on power inversion,followed by the introduction of a multi-dimensional joint array anti-interference technique,including space-time and space-frequency filter,and compare the anti-interference effect of space-domain,space-time and space-frequency filters on the results of the multimode antenna design in the first part of the study.Then a space-time adaptive anti-interference algorithm based on the RLS algorithm with power inversion is implemented on the FPGA platform,and the detailed design process as well as simulation verification results are given.Finally,experimental tests were designed to verify the feasibility of the anti-interference system.