Metasurface-based Antenna Design And Research

With the rapid development of communication technology,spectrum resources are becoming increasingly tight,and the frequencies used by people are gradually moving to high frequencies,from the early longwave and shortwave to the widely used microwave millimeter wave.Due to the short wavelength of microwave and millimeter waves and large path loss,the demand for high-gain antennas is extremely urgent in long-distance communication and radar systems.As a typical high-gain antenna,reflective antennas are widely used in microwave and millimeter-wave frequency bands.In this thesis,we mainly study and design metasurface-based antennas covering four different frequency bands.The main contents are summarized as follows:(1)The metasurface patch unit was researched,and the patch unit suitable for Ku-band and X-band planar reflection arrays was designed,and the amplitude-frequency response and phase-frequency response curve of the unit were obtained through numerical simulation.(2)Based on the designed meta-surface patch unit,two reflective array antennas of different bands were designed using MTALAB program.The first is a Ku-band planar reflective antenna with a mobile feed,which has low-cost planar scanning and high The gain characteristics are different from the previous work that mostly achieved beam scanning by changing the angle of the metasurface or the unit characteristics.This Kuband antenna uses a mobile feed to achieve beam scanning,which is more concise in implementation;the second paragraph It is an X-band planar reflective antenna,which uses a fixed feed source.The antenna has the advantages of broadband and high gain.Then simulated these two antennas and analyzed their performance.(3)The X-band planar reflective antenna is selected for processing and testing,and the maximum gain is 23.498 d B,and the test results are in good agreement with the simulation results.(4)A metasurface antenna is designed by using the angle-cut metal patch unit,which uses the polarization torsion unit to expand the circular polarization bandwidth,and achieves a 10% axial ratio bandwidth,and the beam width of the axial ratio pattern is greater than 100°,It has good circular polarization characteristics and high gain.Compared with other metasurface circular polarization antennas,it achieves a lower profile.(5)A dual-frequency metasurface antenna suitable for 5G millimeter wave applications is designed using a 3×3 metasurface unit with a large center and small sides.The two frequency modes are tuned to 25 GHz and 29.8 GHz.The antenna has the characteristics of broadband and high gain.Compared with the traditional metasurface dual-frequency antenna,the use of aperiodic-sized metasurface unit has more design freedom.