Research On Regulation And Control Of Antenna Beam Scanning Range Based On Metasurface

As a very important electronic device in modern wireless communication,navigation,radio astronomy,remote sensing and other fields,phased array antennas are widely used in various industries.It has extremely broad application prospects in military and civilian fields.If the planar wide-angle scanning phased array antenna can achieve a larger scanning range,the volume of the phased array antenna can be reduced and the production cost can be reduced.The Huygens' metasurface is a highly efficient artificial electromagnetic surface newly proposed in recent years.It changes the transmission amplitude and transmission phase of the unit independently by changing the equivalent electrical permeability and equivalent impedance of each unit on the surface.It is a low-loss,low-cost,easy-to-machine surface that can change the direction of electromagnetic wave propagation.Therefore,this paper overcomes the shortcomings of the traditional spherical radome that is not suitable for processing.At the expense of the maximum radiation direction of the antenna,the Huygens' metasurface is combined with the phased array antenna to increase the scanning range of the phased array antenna.First,this paper introduces the design principle of Huygens' metasurface and the principle of phased array antenna to change the radiation direction.During the analysis,it was found that the electromagnetic waves radiated by the phased array antenna are similar to the plane waves.Therefore,the generalized Snell's law can be used to analyze the influence of the gradient phase metasurface on the radiation direction of the phased array antenna.Therefore,this paper proposes two methods to change the radiation angle of the phased array antenna: 1.Use the nonlinear relationship between the incident angle and the refraction angle in the generalized Snell's law to change the scanning range of the phased array antenna;2.The combination of the gradient phase metasurface's ability to refract electromagnetic waves and mechanical rotation changes the scanning range of the phased array antenna.Simulation results show that these methods have the ability to expand the scanning range of phased array antennas.Then,this paper designs a linearly polarized Huygens' unit with a stable transmission coefficient under oblique incidence of TM waves of-40° to 40°,and designs a gradient phase metasurface lens to change the one-dimensional scanning phased array antenna.Simulation results show that according to the first method,the Huygens' lens with gradient of d ?dx= 40°10mm can expand the scanning range of the 68° phased array antenna by 16%.According to the second method,the Huygens' lens with gradient of d ?dx= 40°10mm can expand the scanning range of the ±34° phased array antenna by 116%.Finally,this paper designs a dual-polarized Huygens' unit that keeps the transmission coefficient stable at an oblique incidence of TM waves of-30° to 30° and that of TE waves at an oblique incidence of-15° to 15°,and the gradient phase metasurface lens designed is used to change the radiation angle of the two-dimensional scanning phased array antenna.Simulation results show that according to the second method,the Huygens lens with gradient d ?dx= 50°23mm can expand the scanning range of the ±20° phased array antenna by 120%.