Fast Analysis And Design Of Metamaterials Based On Antenna-array Theory

Metamaterials,compared to traditional materials existing in nature,are consist of a series of sub-wave units,by which the array are well arranged to control the electromagnetic wave.From the beginning till now,metamaterials have developed from three dimension structures to two dimension surfaces,and further,to digital and programmable metasurfaces.Meanwhile,owing to the large number of units,the size of metasurface is usually electrical large,which would cause large simulation time and high demands on computer performances,and this restricts the efficiency of complex designs.Antenna-array theory only concentrates on radiation performance rather than near fields and other electrical characteristics,and this makes it not only produce believable outcomes,but also reduce the computational time and demands on computer hardwares.Here,the antenna-array theory is used as the analysis tool to design several metasurfaces,which are hard to analysis under traditional simulation softwares.The main contents of the thesis are as follows:1.Realized the antenna-array theory in MATLAB environment,which can analyze the radiation performance of metasurfaces,and obtain the general pattern shape,mainbeam direction,beam width,and sidelobes in the mainbeam area.2.Designed and optimized an X-band dual-functional broadband holographic reflectarray using antenna-array theory.When two horns illuminate in two orthogonal planes,the aperture could produce two pencil beams.3.Designed an equal-gain scanning reflectarray using the antenna-array theory,which can optimize the feed position and make the aperture produce equal-gain pencil beam scanning from 17 degree to 40 degree.4.Designed a 60GHz electrical ultra-large anisotropic transmitting coding metasurface using antenna-array theory.Under the x-polarization excitation,the aperture could generate two independently controllable pencil beams using the concept of holography in coding series;meanwhile,under the y-polarization excitation,the coding metasurface could produce a pencil beam in a large deflection angle(51.6 degree),owing to the convolution characteristic.