The Effective Media Theory Of Metamaterials And Multiple Functional Antenna Applications

With the development of science and technology,people are increasingly limited by the characteristics of traditional materials.Recently,Metamaterials attracts interest,since its special physical properties beyond the traditional media,and have become a major research direction in optics,electromagnetism and physics.Metamaterials are consisted of nonperiodic or periodic unit cells.The metamaterials unit cells can be considered an effective medium,because the physical size of the metamaterial unit cells is smaller than the wavelength of operating frequency.At first,people's research on metamaterials tends to be double negative media,namely negative permittivity and negative permeability,which have special physical phenomena of negative refraction.And with the continuous research on special physical phenomena,wire media and perforated dielectrics have been attracted more attention.Wire media,whose dispersion distribution is presented in a hyperbolic form,have been utilized in imaging,sensing waveguides and quantum thermal energy.And with the easy fabrication and steady permittivity in the wide band,the perforated dielectrics have been realized the lens and clock from transformation optics.In this paper,we mainly study the application of electromagnetic field in the wire media and perforated dielectrics,and apply them in the terms of bi-functional antennas.The main contents of this article are as follows: 1.We demonstrate the effective media theory,electromagnetic parameter extraction method and the Fermat's principle.We demonstrate and verified the characteristics of periodic perforated dielectrics and wire media by the full wave simulation.2.We demonstrate the bi-functional zone plate reflector and bi-functional zone plate lens.We start with gradient-index zone plate reflector and lens,demonstrate that such a reflector and lens could also function as a lens with end-fire emissions when integrated with a dielectric phase compensation layer.We practically implement the proposed design through drilling subwavelength holes with different sizes in a dielectric host medium,and the perforated zone plates demonstrate the functionalities of generating both broadside and endfire radiations in a broadband frequency range.3.We demonstrate the bi-functional zone plate lens.We start with gradient-index zone plate lens in the broadside direction,and utilize the electromagnetic characteristics of the wire media to realize the multi-beam in the end-fire direction.