Metasurface Based Frequency-reconfigurable Microstrip Antenna

Metasurface is one of the popular research fields in recent years,it is a two-dimensional planar metamaterials structure.The periodic or aperiodic structure that made of metal element tend to has specific electromagnetic properties.Microstrip antenna is indispensable equipment in the area of communications,it is favored by the engineers because of its small volume,light weight and easy with carrier integration advantages.It is severely restricted in the engineering applications by narrow bandwidth.Combine special structure of metasurface with microstrip antenna can be productive microstrip antenna's performance.In this paper,three kinds of metasurface were designed,the structure of them are petals,gridiron and scale.Petals metasurface was used to control the electromagnetic wave,realized low reflection and high RCS reduction of vertically incident electromagnetic wave.The other two kinds of metasurface structure combined with microstrip antenna realized the frequency of the reconfigurable microstrip antenna.This paper designed a flexible coding metasurface control electromagnetic wave.The experimental result show that the reflectivity is-15 dB for coding metasurface can be achieved at 8.4GHz,and the RCS reduction as compared with a bare metallic plate with the same size is average 10.0dB.The characteristic of RCS reduction can be kept up as the coding metasurface is wrapped around a cylinder with a diameter of 7cm,and the RCS reduction is average 7.8dB.This design breakthough the restriction of traditional rigid material on the material selection of medium,it provide a new way to control electromagnetic wave and has important research significance in microwave radar.The microstrip antenna's frequency was reconstruction by grid and scale metasurface.We got a narrow bandwidth for frequency regulation of microstrip antenna with grid metasurface,adjusting effect is not obvious.The structure of metasurface was scale can regulate the frequency of the microstrip antenna from 7.8GHz to8.6GHz,this frequency band include the upward bandwidth of X-band in satellitecommunication,and it has a potential application for satellite communications.The complex RF system aren't introduced by machinery regulating,and this way can get a small effects on the antenna's gain also maintain a higher level in the regulation band,and this metasurface attain the goal of the initial design.We tested the physical model,and the result keep a good agreement with simulation results.