Research On A New Type Of Antenna Based On Traveling Wave Mechanism

As the link between high-frequency guided waves and radio waves,the antenna plays an important role for transmitting and receiving radio waves in a communication system.The antenna with traveling wave radiation mechanism is a common form of antenna.The leaky wave antenna is one of the traveling wave antennas.It has the advantages of low profile,narrow beam,wide frequency band,simple feeding structure,and the beam pointing angle changes with frequency.Because of the advantages of this antenna,it has been widely used in radar scanning,satellite communication and other related fields.With the rapid development of 5G communication and Internet of Things technology,the number of terminals has increased exponentially,and the era of Internet of Everything has entered.Requirements for communication systems such as low delay,high transmission rate and wide bandwidth are put forward.Leaky wave antennas are used as a solution to the above problems.One direction,especially the high scan rate leaky wave antenna.In this paper,the working principle of the leaky wave antenna with traveling wave radiation mechanism is reviewed firstly,and a wide-sweep Angle leaky wave antenna based on planar microstrip line structure is designed through in-depth analysis of the periodic leaky wave antenna.The design of the antenna adopts the symmetrical form of U-shaped microstrip line with gap,and the beam scanning rate of the antenna can be changed by adjusting the width of the gap without changing the working frequency of the antenna.Stubs are arranged on both sides of the U-shaped groove.Improve the impedance matching of the antenna.The designed antenna is optimized and manufactured.The actual measurement results show that the antenna working frequency band is 5.95GHz-7.1 GHz.With a relative bandwidth of 17.6%,the beam can continuously scan from-60° in the backward direction through the side of the ship to +58° in the forward direction.The scanning rate of the antenna can reach 103°/GHz,which suppresses the open-stop band effect.In addition,the designed antenna has an average radiation efficiency of over 90% in the working frequency band,and the fluctuation of gain in operating frequency band is less than 2 d Bi,which shows a good gain consistency.In the study of improving the beam scanning rate of the antenna,a high scanning rate leaky wave antenna is designed using the theory of group velocity delay.It adopts a symmetrical structure of the plane periodic unit,and a slender is designed on one side of the main microstrip line.Stubs,on the one hand,in order to improve the impedance matching of the antenna,on the other hand,it also helps to increase the group speed delay to improve the scanning rate of the antenna.An I-shaped slot is set at the bottom of the antenna to continue to increase the group speed delay to further improve the beam scanning rate.The simulation and actual test results show that the antenna beam can be scanned continuously from backward to forward.The working frequency of the antenna is 4.8 GHz-5.34 GHz.The scanning angle of the antenna beam can be from backward to within a relative bandwidth of 10.6%-Continuous scanning in the range from 62° to +65° in the forward direction,the scanning rate of the antenna can reach 235°/GHz,which is 128% higher than the first wide leaky wave antenna.