Research On Electromagnetic Wave Manipulation Using Waveguide Integrated Feeding Metasurface

With the development of society,science and technology,all aspects of social life are closely related to electromagnetic waves,and the realization of high-efficient manipulation of electromagnetic waves has become an important aspect for the further development of science and technology.The interaction between electromagnetic waves and various substances is one of the important research fields of science.Huygens' metasurface is a kind of high-efficient artificial electromagnetic material which attracts much attention recently.By designing a structure with specific size,the equivalent electrical impedence and magnetic impedance of the surface can be changed,realizing full control of the transmission response of the element.Therefore,based on the excellent transmission characteristics of Huygens' element,a kind of metasurface fed by low-profile rectangular waveguide with adjustable phase gradient is designed,Such kind of waveguide antenna structure with metasurface loaded greatly improves the efficiency of the antenna.The whole structure is easy to be fabricated and installed,which provides a solution for the design of low-profile and intergrated antenna.Firstly,the phase gradient theory,the radiation theory of the waveguide Orient field,the general Snell's law and other related principles are analyzed in detail.It is demonstrated that Huygens' principle and Snell's law are combined to provide theoretical guidence for the design of metasurfaces.A double-beam rectangular open waveguide with high radiation efficiency is designed based on the radiation theory of waveguide orifice field.At the same time,this paper designs a kind of Huygens' element with angle consistency,which could cover whole the transmission phase of0-2?with high transmission efficiency.Then 7 groups of elements are selected to analyze the stability of transmission response under different incident angles,the phase interval is 2?/7.Based on the 7groups of elements,a 30×43 metasurface structure was designed,and multifocal holographic imaging was realized in the near field,verifying the stability of transmission response of the designed metasurface.According to the theory of phase gradient metasurfaces,12 groups of Huygens' metasurface with different phase gradient are constructed with size of 16×4 unit cells,which are loaded on the rectangular open waveguide orientations to regulate the direction of electromagnetic beam radiation.The deflection Angle of electromagnetic wave covers the range from-73° to 73°.Several groups of structures with better results were optimized,simulated and measured,and the measured results were in agreement with the theoretical results.Finally,a active component is introduced into the reconfigurable Huygens surface element designed to control the deflection angles of the electromagnetic wave beam dynamically by changing the on-off state of component.The beam deflection angle from 0 to 40°is realized,and the simulation results are in good agreement with the theoretical analysis,which provides a effective way to control the angle of the deflection wave in real time with low-profile waveguide-fed metasurface.