Design Of Circularly Polarized Microstrip Antenna Array

In recent years,with the rapid development of modern wireless communication technology,the circularly polarized microstrip antenna array has been widely used due to its compact structure,light weight,strong anti-interference ability and easy integration of integrated circuits.This paper first introduces the background and significance of the research topic,and then introduces the research status of the circularly polarized microstrip array antenna at home and abroad.Finally,based on the existing research and the related theoretical basic knowledge,two circular polarizations are designed.The microstrip antenna array is basically consistent with the results of the simulation.The main research contents of this paper are summarized as follows:Firstly,a broadband circularly polarized microstrip antenna array design with a back circular groove structure is proposed.The four-element antenna array is realized by using a microstrip antenna having a back circular groove as an antenna unit and extending a rectangular groove on the back groove to enhance the axial ratio bandwidth of the antenna unit,and then using a sequential rotary feed network.The overall size of the array antenna is46×46×1.6mm~3.According to the measured results,the obtained impedance bandwidth is72.9%(4.62-9.92GHz),the 3 dB axial ratio bandwidth is 62.2%(4.48-8.52GHz),and the polarization of the array antenna is right-handed polarization.The compact size,wider impedance bandwidth and axial ratio bandwidth,higher gain,and proper radiation characteristics all indicate that the array antenna is more suitable for wireless communication systems.Secondly,a broadband circularly polarized antenna array design based on frequency superposition is proposed.First,the element antenna is operated in different frequency bands by changing the size of the unit patch,the long axis and the short axis of the elliptical slot.Second,the sequential rotation feed network is designed.Finally,four different elements are rotated in turn and connected to the sequential rotary feed network.The overall size of the circularly polarized array antenna is42×42×1.6mm~3.According to the measured results,the designed antenna array obtains an impedance bandwidth of 21.2%(5.66-7GHz)and an axial ratio bandwidth of 11.3%(6.16-6.9GHz),and the polarization mode of the array antenna is right-hand circularly polarized.