Research On Mutual Coupling Effects Analysis And Pattern Synthesis Techniques Of Antenna Array

Compared with a single antenna,the antenna array has the characteristics of high gain,low sidelobe,strong directivity,narrow beam and so on,and it has been applied in many fields,such as radar,communication and navigation.In recent years,with the rapid development of these fields,antenna array is gradually developing towards the direction of high performance and large scale,and the calculation and optimization of radiation and scattering of large antenna array have become a hotspot in the research.In this thesis,some studies on these problems of large antenna array are carried out,including: high-efficiency and highprecision calculation of radiation field and scattering field of large antenna array,optimization of radiation pattern of antenna array,and comprehensive optimization of radiation and scattering of antenna array based on electromagnetic canceling.The main research work is as follows:Firstly,aiming at the problem of high-efficiency and high-precision calculation and optimization of radiation field of large antenna array,a high-performance algorithm based on subarray strategy combined with radiation pattern of active element is studied,and the algorithm is used to verify the calculation of radiation field of large linear array,planar array,circular array and elliptical circular array,which solves the high-efficiency and highprecision calculation of radiation field of large array with more than ten thousand array elements on a single machine.With the same accuracy as the full-wave simulation method,the computation memory and time requirements are significantly reduced.By combining the high performance calculation method with the optimization algorithm,the radiation field of the large phased array fed parabolic cylindrical antenna is calculated and optimized.The experimental results show that the array solving and synthesis algorithm designed in this thesis can efficiently and accurately calculate and optimize the radiation characteristics of large antenna array with different array aperture and form,which provides an effective software platform for the evaluation and design of radiation characteristics of antenna array in engineering.Secondly,the scattering calculation of antenna array is analyzed theoretically.In order to solve the problem that it is difficult to extract the scattering field in each element array of subarray by simulation software and test method when using subarray method to calculate the scattering field of large array,a field separation calculation method of element array based on simulation software and test method is proposed through complete formula derivation.Based on the research of radiation calculation and optimization of large array,a high-efficiency and high-precision calculation method of large array scattering is derived,which combines subarray strategy with induced element pattern.The proposed method is verified by the scattering calculation examples of large linear array and planar array,the results show that this method can reduce the scattering calculation problem of large antenna array to the electromagnetic calculation problem of subarray.The requirements for computing memory and computing time are greatly reduced under the premise of obtaining the same accuracy as the FEKO simulation software(Method of Moments,MOM),and the high-efficiency and high-precision calculation problem of large-scale antenna array electromagnetic scattering characteristics on a single machine is solved.Finally,aiming at the problem of in band and out of band co polarization radar wave stealth design of ultra wideband antenna array,based on the above array radiation and scattering calculation method,combined with high-performance intelligent optimization algorithm,a comprehensive optimization method of antenna array radiation and scattering based on electromagnetic cancellation strategy is proposed.By optimizing the feed amplitude and phase of each element at the same time,the active cancellation of radiation field and scattering field,side lobe level suppression of radiation pattern,gain loss minimization,beam direction and width control are realized.The experimental results of linear polarization tightly coupled antenna array and dual polarization tightly coupled antenna array show that the proposed method can realize the above two pairs of electromagnetic cancellation When the antenna array radiates beam with wide angle and low sidelobe scanning,it can suppress the monostatic and bistatic scattering level of the antenna array to more than 10 d B.At the same time,it also has good stealth effect for the same polarization radar wave out of band.