Design Of Spaceborne Dual Polarization Antenna Array

With the continuous development of science and technology,how to implement the monitoring of changes in the global atmosphere,ocean and other environments is a hot topic that many scholars have been working on.In this paper,we will study the antennas on satellites that monitor changes in ocean salinity.Since subtle changes in ocean salinity will reflect different effects,satellites are required to have high precision characteristics.The high-precision characteristics are determined by the performance of the on-board antenna,so this topic will be based on the research background to design a spaceborne antenna that meets the requirements.Moreover,in the complex and variable outer space electromagnetic environment,the performance of the antenna is not only determined by its own structural design,but also the influence of the surrounding physical environment.It is,thus,necessary to consider the star environment,thereby improving the influence of the external factors on the antenna radiation pattern.The interference of the pattern.Therefore,the research of this subject has practical application value.The main research contents are as follows:Firstly,a dual-polarized microstrip patch slotted antenna was designed,which uses a coaxial four-point inverter feed.Two quarter-two Wilkinson power splitters are used to achieve equal-radiation inversion,and the narrow-bandwidth characteristics of the microstrip antenna are compensated by slotting the circular radiation patch,and the high-order mode is suppressed by loading the short-circuit pin.Finally,a circular metal wall is applied around the patch to broaden the beam and provide some protection.Since the antenna is applied to a satellite,the antenna should be miniaturized and lightened as much as possible.Therefore,for this purpose,the above structure is improved,where a large coupling amount is obtained by using a small H slit to realize coupling feeding and adopting the L probe feed mode to compensate for the capacitive loss caused by the reduction of the patch antenna,that is,the two coaxial coupled feeds are used instead of the previous coaxial feed.The photonic crystal structure is introduced to achieve miniaturization and improve the performance of the antenna.The antenna is finally processed and tested.Secondly,through the understanding of the antenna array on the satellite studied in this subject,from the practical application point of view,the analysis and discussion of the array element spacing.In addition,in the unpredictable outer space,the complex and variable electromagnetic environment will has a negative impact on the performance of the antenna on the satellite.By analyzing the influence of the star environment on the radiation pattern of the antenna,the design of the array cavity is used to improve and eliminate the influence of the star environment on the antenna pattern.Finally,since the proposed antenna array has a large number of array elements,the calculation of the radiation field of the array must be considered.Therefore,the antenna array is calculated by the active element pattern method.Not only the mutual coupling effect between the array elements are considered,but also the influence of environmental factors on the antenna array.The active element pattern of the array is extracted by this method,and the selection of the mapping sub-array is performed,and then the radiation pattern of the array is finally calculated.Last,compared with the full-wave simulation in HFSS,the feasibility and effectiveness of the method are verified.