Establishment And Analysis Of Electromechanical Coupling Model Of Space-based Active Phased Array Antenna Based On Element Shape Change

The space-based active phased array antenna is widely used in many fields,such as space communication,remote sensing,electronic reconnaissance,navigation,environmental monitoring,etc.,but it also has the characteristics of large size and light weight.Due to the influence of satellite attitude shaking,mechanical vibration and space harsh temperature environment,the array antenna is prone to structural deformation,affecting the beam pointing accuracy of the antenna,resulting in the electrical performance of the antenna Lower.As one of the main forms of space-based active phased array antenna,the structural deformation of space-based microstrip array antenna will not only lead to the displacement and deflection of antenna element position,but also the change of antenna element morphology due to local deformation,resulting in the change of radiation pattern,which directly affects the electrical performance of the antenna.For this reason,the electromechanical coupling problem of the array antenna has become one of the bottlenecks in the development of the space-based active phased array antenna.In this paper,the coupling relationship between the structural deformation and the main radiation performance parameters of the antenna is analyzed in depth.The main contents of this paper are as follows:(1)Based on the equivalent size method and dyadic Green's function method,the expression method of the mutual coupling between elements is studied,and the electromechanical coupling model of the mutual coupling between elements and the physical shape of elements is derived.Then a 2 * 2 array of microstrip cells with morphologic changes is established in HFSS,and the results of HFSS simulation are compared with the results of coupling model.From the results,it can be seen that when the bending radius of microstrip cells in the same row is greater than 21 mm,the bending radius of microstrip cells in the same row is greater than 24 mm,and the bending radius of diagonal microstrip cells is greater than 16 mm,the calculation errors of the two are obvious Less than 5%,which verifies the correctness of the coupling model.Finally,based on the mathematical representation of the deformation element pattern function,the element pattern function considering the influence of mutual coupling is derived.(2)Based on the pattern function of microstrip element under the change of topography,it is applied to the electromechanical coupling model of array antenna.Firstly,the working environment of the satellite array antenna is analyzed,and the influence factors of the element shape change are added to the electromechanical coupling model of the array antenna.Then four groups of deformed antenna arrays(8 * 2 array of microstrip elements,with the minimum bending radius of 0,2 ?,? and ? / 2 respectively)are established in HFSS according to the actual working conditions.The correctness of the coupling model of array antenna is verified.From the results,it can be seen that the maximum relative error value of the two is 2.85%,which can meet the engineering requirements.The results show that the gain loss of 0.5d B reaches the critical value in the process when the maximum deformation of symmetrical deformed array is 9mm,and the gain loss reaches the critical value in the process when the maximum deformation of asymmetric deformed array is 24 mm Value.The deformation critical value calculated by the coupling model can provide effective guidance for the actual engineering antenna design.(3)According to the electromechanical coupling model of the array antenna based on the shape change,a fast calculation software of the radiation performance of the satellite active phased array antenna based on the shape change of the element is developed by using C + + Builder software.Through the software,the change of the performance parameters of the satellite array antenna when the structure of the antenna array is deformed can be calculated quickly and effectively.The overall design idea and the specific contents of each module of the fast calculation software for the radiation performance of the space-based active phased array antenna based on the change of element shape are summarized in detail.Finally,the whole process of the radiation performance analysis of the satellite array antenna with structural deformation is completed by an example,which verifies the practicability and effectiveness of the software.It provides a fast calculation method for analyzing the influence of space environment on phased array antenna.