Design Of Dual-Polarized Microstrip Antenna For Spaceborne Application In L-Band

With the rapid development of communication industry in recent years,the fifth generation wireless communication technology will be promoted soon.As an indispensable component of communication system,antenna plays an important role in information transmission.In this thesis,we need to design an L-band satellite antenna for ocean salinity detection.According to the needs of the project,optimize the dual-polarized microstrip antenna unit designed in the early stage,they will compose of antenna array for simulation and analysis.In this thesis,the main work is as follows:1.In order to meet the requirements of the array,the dual-polarization microstrip antenna unit designed in the early stage is improved.After modifying the antenna shape,rotating polarization direction and adding heat insulation structure,six antenna units are redesigned.It can effectively save space resources on the satellite,and ensure the polarization direction of all units are consistent after forming the array.The electromagnetic simulation software is used for simulation.In the bandwidth range,the VSWR of the antenna unit is below 1.25,the cross polarization level is below-25 d B,and the half power beam width of each section of the radiation pattern of the antenna is above 70 °,which meets the requirements of the index,and the radiation patterns of different antenna units have good consistency.2.Two kinds of antenna arrays are composed of the designed antenna units,each of them is composed of 56 units and arranged in "Y" shape.The simulation software is used to simulate the whole model of antenna array and simulated star.We can get the consistency of amplitude and phase of radiation pattern of each unit in the array,and the average value of half power beam width of all azimuth sections of radiation pattern of each unit by analyzing the simulation results.The polarization purity is defined to reflect the isolation of two polarization modes in the array.Comparing the results of the two antenna arrays,the first one is better,the amplitude consistency is less than 0.14 d B,the phase consistency is less than 5°,the polarization purity is up to-20 d B,the average beam width is more than 66 °,and all the indexes meet the design requirements.Finally,the end of thesis sums up the whole work,points out the shortcomings and the need for improvement,and clarifies the follow-up work direction.