Design And Research Of Beam-Scanning Antenna

The beam-scanning antenna can achieve communication in multiple target directions,which can effectively improve the communication efficiency,but there are problems of narrow scanning range and high cost.This paper designs beam-scanning antenna based on composite right/left-handed theory,the transmission line impedance transformation theory and liquid crystal electronic control theory,focusing on how to improve the scanning range,reduce size and cost.The specific research contents are as follows:1.Research on frequency scanning antenna based on composite right/left-handed structure.The theory of composite right/left-handed transmission line is studied,the microstrip plane composite right/left-handed structure unit is designed based on the transmission line impedance transformation theory.The antenna array is designed to achieve frequency scanning.The results show that in the frequency band of9.3GHz-10.9GHz,the beam can be deflected from-50°to+55°,and the peak gain is13.5d B.Compared with the traditional frequency scanning antenna,the scanning range and gain are increased,the design complexity and cost are reduced.2.Research on fixed frequency beam-scanning antenna based on half-mode corrugate substrate integrated waveguide.Based on the transmission line impedance transformation theory to design half-mode corrugate substrate integrated waveguide,and inverted U-shaped slots are introduced to design composite right/left-handed structures,which effectively reduces size and cost of the antenna;variodes are introduced into the inverted U-shaped slots to design tunable composite right/left-handed structures,by increasing the proportion of the variodes to widen the scanning range.The antenna achieves the scanning range is 124°at 4.2GHz.3.Research on circularly polarized fixed frequency beam-scanning antenna based on liquid crystal.The electronic control principle of liquid crystal is studied and a liquid crystal phase shifter is designed,coupling feed branches are introduced behind the phase shifter units to realize the beam control of the antenna.The orthogonal slot is introduced into the microstrip antenna to generating circularly polarized waves.The scanning range is±20° at 12.6 GHz,and antenna maintains a circular polarization during the scanning process.The antenna has small size and low loss,which achieves the design purpose.