| With the rapid development of modern communication technology and the advent of the 5G era,the requirements for controlling the propagation of electromagnetic waves are getting higher and higher,which are most obvious in the fields of antennas,satellite communications and military.In order to control the propagation of electromagnetic waves,the related research on electromagnetic wave regulation is essential.Studies have shown that the control of electromagnetic waves can be achieved by designing the unit structure and arrangement of the phase gradient metasurface.It has the advantages of simple design,low cost,small size,easy conformality,wider application range and higher beam precision control.In this paper,three metallic beam steering devices with different functions are designed based on reflection and transmission phase gradient metasurfaces.Through the relevant theoretical analysis and structural design of the reflection and transmission beam controllers,the basic unit parameters are optimized and analyzed.The designed beam controller has the advantages of functional diversity and high work efficiency.Among them,the first part designs a cross-polarization beam steering.It can realize the regulation of 0～2π reflected wave phase and the electromagnetic wave regulation function of linear-linear polarization.Through experimental simulation,it is found that in the frequency range of 11.86 GHz～20.3 GHz,the cross reflection efficiency can reach 98%,and the maximum difference between the deflection angle of the reflection angle and the theoretical calculation value is:All are less than-20dB.In the second part,two reflective co-polarized beam steering devices with different structures are designed.All of them can realize the phase control of 0～2π,and can realize the electromagnetic wave control function of circular-circular polarization and linear-circular polarization.The simulation results show that the polarization conversion efficiency of the’bend I-shape’ is 99%at 18.8GHz～33.9GHz.The polarization conversion efficiency of the’double arc’ is as high as 90%at 13.4GHz～28.1GHz.Comparing the deflection angle of the reflected wave with the theoretical calculation,the maximum difference between the’bend-shaped’ structure and the incident left-handed circularly polarized wave is 1.1°,and the maximum difference between the ’double-arc’ structure is 2.75°.The actual samples were produced for measurement and analysis,and their working bandwidths were basically the same.The measured reflectances of the samples were all less than-15 dB,and the results were basically consistent with the theory.In the third part,a transmission beam controller is designed,which realizes the functions of linear-circular polarization and 0～2π phase regulation of reflected waves.The simulation results show that the operating bandwidth is 18GHz～19GHz.The theoretical calculation value of the transmission deflection angle at 18.3GHz is,and the simulation result of the singular transmission angle is basically consistent with each other.The normalized far-field scattering curves and near-field electric fields at different frequency points were monitored.The results show that between 18GHz and 19GHz,when the linearly polarized wave is vertically incident on the beam steering,the linearly polarized wave can be converted into a left-handed circular pole,and right-hand circularly polarized waves.The three beam controllers with different functions designed in this paper have the advantages of high polarization conversion efficiency,wider operating bandwidth,and the reflection angle and transmission angle are closer to the theoretical values,providing a new reference direction for beam steering technology. |
