| Antenna test is an important means to evaluate the performance of the antenna.Generally,in order to test the radiation performance of the antenna accurately,an ideal test environment with a pure electromagnetic environment is built.However,the non-ideal absorbing environment is formed due to the damage of the absorbing material or the area where the absorbing material is not laid.So it is necessary to study the antenna test technology under non-ideal environment to improve the accuracy of the antenna test.Due to the faults of the phased array antenna,the radiation pattern of the array element is distorted,and even the radiation performance of the entire phased array antenna is reduced.In order to diagnose the faulty unit of the phased array antenna,it is necessary to study a fast and accurate method to determine the excitation amplitude and phase of the unit.The author’s major contribution are summarized as follows:1.The theory of spherical wave expansion is studied and analyzed.A multipath interference suppression technology based on MARS is proposed to solve the problem of the multipath interference encountered in the antenna test in the non-ideal absorption environment,which is to start from the total radiation field obtained by the test.The spherical wave expansion theory and mode filtering technology are combined to eliminate the influence of multipath interference on the test antenna pattern.The coordinate translation of the antenna pattern and the selection of the mode filter function involved in this technique are analyzed in detail.The test simulation models of the interfered antenna are established in the FEKO simulation software and the actual measurement scenes are set up in a microwave anechoic chamber,the obtained radiation datas of which are corrected by this technology,which verifies the effectiveness of the technology in suppressing multipath interference.The results show that with this technique,the multipath interference in the antenna test can be significantly suppressed,and the multipath interference suppression in the antenna single-frequency test can also be achieved,and the influence of external radiation interference on the pattern of the antenna under test can be effectively eliminated.2.A feed amplitude and phase calculation method for phased array antennas based on pattern filtering technology is proposed to realize the fault diagnosis of phased array antennas.The radiated field of each element is separated from the total radiated field of the phased array antenna by using pattern filtering technology,and the excitation amplitude and phase of the corresponding element are inverted based on the radiation field of the element.Using the calculation method to diagnose the fault of the phased array antenna,the diagnosis cost is reduced and the diagnosis efficiency is improved.The possible fault types of the phased array antenna are studied.For these possible fault types,the simulation models of the Vivaldi phased array antenna in the fault state are established in the FEKO simulation software.The attenuator fault and phase shifter fault of the antenna in different degrees in different beam orientations are diagnosed by using this calculation method.The simulation results show that the fault location of the phased array antenna can be effectively diagnosed using this method,which verifies the feasibility of the calculation method in fault diagnosis. |
