Design Of Circularly Polarized Antennas Used In Wireless Communication Systems

Today’s 5G communication system has developed rapidly,the Beidou navigation system,RFID radio frequency identification,and millimeter wave communication system,etc.are also rapidly advancing.These new era communications systems have also become more stringent in the requirements of antenna performance.For the strict requirements of wireless communication systems in different application scenarios,the circularized antenna is developed towards array,miniaturization,multi-frequency,high gaining and broadband.From the actual application,this paper has launched in-depth discussions and analysis of new technologies such as circular polarization array antenna,broadband circularly and millimeters,and the main research contents of this paper can be summarized as follows:(1)High gain circular polarization antenna array of sequential rotation feed.Firstly,a circularized antenna unit based on H-type gap-coupled feed is designed,and its structural evolution process is analyzed.The antenna unit is mainly to achieve circularly radiation through the phase difference between the two H-type gaps.Since the axial ratio bandwidth and impedance matching bandwidth of the antenna unit is narrower,a 2×2 sequential rotation of the antenna array is designed to increase the impedance matching bandwidth of the antenna and the axis ratio bandwidth.In order to further improve the gain of the antenna,a serial network is designed to extend the 2×2 array to 4 ×4 sequential rotation of the antenna array.After processing test,the impedance matching bandwidth of the antenna array is 1.81-1.93 GHz,and the axial ratio is 1.82 GHz-1.93 GHz,the maximum gain is 17.4 dbi.(2)Broadband circular polarization antenna of the branches.First,the L-type feed probe is used for the coupling feed of antenna radiation patch to improve the impedance matching bandwidth of the antenna.A broadband 90 ° phase shifter and broadband WILKINSON power is designed,and its theoretical calculation process is given.Based on the broadband phase shifter and broadband power,a broadband is designed with a broadband,the phase difference is 0 °,-90 °,-180 °,-270 °,respectively.The broadband feed network and the Ltype probe are used to couple the radiation patch,and the processed test verification,the antenna impedance matching bandwidth is 0.97 GHz-2.64GHz(92.5%),3DB axis ratio is0.9 GHz-2.85GHz(104%),the maximum gain is 5.34 dbi.(3)Broadband high gain millimeter wave circulation array antenna.The antenna has four radiation patchs,both by gap-coupled.Four radiating patches are connected to the ground to produce nhavilion by introducing an L-type branch and a square inquiore,thereby generating two orthogonal modes,forming a circularly radiation.Finally,a plurality of power-fed networks such as oneyear-equivalent power score will extend the antenna into 4 ×4 arrays to increase the gain of the antenna.After simulation optimization,the impedance matching bandwidth of the array antenna was 37.72 GHz-48.26GHz(relative bandwidth of 24.5%),and the 3DB axis ratio was 39.83 GHz-48.55GHz(relative bandwidth of 19.8%),the maximum gain was 19.14 dbi.