Research On The Subwavelength Imaging Using Metamaterials

Artificial electromagnetic metamaterials gain more and more attentions and research of the academics in recent years,because of its novelty electromagnetic properties and different from the natural materials.The electromagnetic properties of metamaterials can be controlled by independently changing the sub-wavelength structure of the artificial electromagnetic materials,so that any transmission of electromagnetic waves in accordance with the wishes of the people,to achieve regulation of electromagnetic waves flexibility.In the realization of sub-wavelength imaging,the electromagnetic metamaterial has a unique role and can overcome the diffraction limit of traditional imaging systems.The dissertation mainly focuses on the analysis of the sub-wavelength imaging by using artificial electromagnetic metamaterials,the main attributions of this dissertation are listed as follows:1.A subwavelength imaging design based on periodic metal wire media arrays is proposed.An imaging system is constructed using the periodic arrangement of sub-wavelength-sized metal wire media,which breaks the diffraction limit of conventional imaging systems and realizes sub-wavelength imaging.In the simulation process,the influencing factors of the sub-wavelength imaging effects of the metal wire media are studied in detail,including the effects of changes in the array structure parameters of the metal wire media and changes in the feed structure on the imaging system.In addition,the electromagnetic imaging characteristics of bending metal line media arrays were studied and analyzed,including the influence with the length of bending metal lines and the bending angle on subwavelength imaging.2.For the limitation of periodic metal wire array in subwavelength imaging,the design of loading Epsilon Near Zero(ENZ)material is proposed to solve the corresponding imaging problem.And the electromagnetic imaging characteristics is studied in here.The combination of ENZ material and the air as the substrate media,it not only breaks the limitation of the metal wire length in the periodic metal wire media array structure,realizes sub-wavelength imaging with any metal wire media length,but also solves the imaging problem caused by the bending angle,making it possible to have a good electromagnetic imaging effect at any angle.3.A subwavelength imaging design in WR90 waveguide is proposed,in which a metal line media array structure is loaded on a straight waveguide or a sharp bending waveguide,the electromagnetic imaging design can be achieved regardless of whether the waveguide exhibits electromagnetic band pass characteristics or band-stop characteristics,and the use of arrays of metal wire media of different length dimensions can achieve better subwavelength imaging within any sharp bend waveguide.