| The biggest difference between the conformal bearing antenna and the traditional antenna is that the conformal bearing antenna has both antenna radiation performance and structural bearing function,and is part of the carrier platform at the same time.This kind of antenna has two obvious characteristics: on the one hand,the structure part and the antenna part are mutually coupled and affect each other,which restricts the electromechanical performance of the antenna itself;On the other hand,the effect of external environment loading degree on the carrier platform will not only cause the overall deformation of the array antenna,but also lead to the structural deformation of the array element itself,the position change of the array element and the direction deflection.All these changes will affect the electrical performance of the antenna.The above structural parameters(including structural geometric size,material physical parameters,etc.)and structural deformation are collectively referred to as structural factors.For the UWB conformal bearing antenna,the coupling relationship between the bearing part and the antenna part is more complex because of its wide working bandwidth and many structural factors.Therefore,in order to design high performance UWB conformal bearing antenna and ensure its stable operation in practical engineering,it is necessary to reveal the mechanism of the influence of structural factors on the electrical performance of UWB conformal bearing antenna.Aiming at the influence of internal structural parameters and external structural deformation on the electrical performance of UWB conformal bearing antenna,this paper carried out the relevant mechanism research,designed and processed samples,and completed the electrical performance test.The main work is as follows:(1)An omnidirectional ultra wideband conformal bearing antenna with sandwich structure is designed,which can achieve impedance bandwidth of 9 times frequency(operating in the frequency range of 2GHz-18GHz).On this basis,the influence mechanism of the thickness of the skin,the height of the foam and the dielectric constant on the electrical properties of the sandwich antenna was analyzed.According to the influence mechanism,through continuous optimization,the parameter information of each part of the structure is determined,and the final structure scheme of the conformal bearing antenna is obtained.Finally,the sample antenna is fabricated and its electrical performance is tested.The test results show that the electrical performance of the sample antenna is in accordance with the expected design,that is,the sandwich structure UWB conformal bearing antenna designed according to the above influence mechanism has a good electrical performance.(2)The existing relationship between the influence of structural errors on the electrical performance of the array antenna only considers the spatial phase change caused by the antenna position error,and does not consider the influence of the element deformation on its orientation pattern.In order to solve the above problems,this paper takes the wing conformbearing UWB antenna element model as an example(working in the frequency range of100MHz-600MHz),studies the electromagnetic analysis method of the wing antenna structure after deformation,and simulates and analyzes the influence of different deformation angles on the antenna element pattern.The simulation results show that the structural deformation will not only affect the impedance matching of the antenna and reduce the operating bandwidth of the antenna,but also affect the gain,un-roundness,crosspolarization Ratio and other characteristic parameters of the element pattern.Finally,the sample antenna is processed and the structure deformation experimental platform is built to test the electrical performance of the sample antenna itself and the electrical performance of the sample antenna under different deformation angles.By comparing the results of the above two groups of experimental data with the simulation data,the correctness of the influence law of the above structural deformation on the electrical performance of the antenna unit can be verified.(3)Combined with the conclusion of point(2),taking the UWB wing conformal bearing antenna as an example(operating in the frequency range of 400MHz-2000MHz),full-wave simulation is carried out in HFSS.Then the antenna elements are combined into an array antenna,and the electrical performance of the array antenna is analyzed.Based on the structural deformation model of the array antenna,the changes of the array element's own direction pattern and characteristic parameters after structural deformation,as well as the changes of the overall electrical performance of the array antenna are analyzed,and the influence mechanism of structural deformation on the electrical performance of the UWB conformal bearing array antenna is obtained.The analysis results show that,compared with the array element position change and beam direction change caused by structural deformation,the parameter change of the array element itself is more serious and has a greater impact on the performance of the array antenna. |
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