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Microwave Different To The Experimental And Theoretical Study Of Media

Posted on:2006-10-16Degree:DoctorType:Dissertation
Country:ChinaCandidate:Q SuiFull Text:PDF
GTID:1118360182957568Subject:Electromagnetic field and microwave technology
Abstract/Summary:PDF Full Text Request
Composite meta-material, which has both negative permeability and permittivity simultaneously within some frequency ranges, is a great discovery on Physics and Electromagnetism in this century. There have been breakthroughs in classical electromagnetic concepts through the study of the meta-material. The in-depth research results can be applied to many fields in the future. Composite meta-material is one of the frontiers of Physics and Electromagnetism in the past few years. In this paper, the meta-material constructed by periodically interspaced conducting nonmagnetic split ring resonators (SRRs) and continuous metallic wires is studied by experiments and the Finite-Difference Time-Domain (FDTD).The main works and innovations of experiments are as follows:1, A large composite meta-material is made of metallic rods and SRRs. The transmission properties within the meta-material are studied. The results show that the effective permittivity and permeability were simultaneously negative in certain frequency range, when the direction of the electric field is parallel to the periodically arranged wires and the magnetic field is parallel to the axis of the rings in the periodic arranged SRRs.2, The radiation pattern of monopole in the meta-material is studied. It is found that the monopole in the meta-material is directional while it is nondirectional without the meta-material. The phenomenon of negative refraction on the interface between meta-material and the air is also observed.3, The test device for prism measurement has been completed. Two triangular prisms made of Teflon and meta-material are used in the experiments. The experiment is about the oblique incident radiation on interface. The negative Snell' s law on the interface between meta-material and the air is verified.In this paper, the three-dimensional FDTD method is used to simulate the electromagnetic waves traveling in meta-materials of three shapes of slab, prism and cylinder. Some new techniques and models are used in the simulation. For example, two-directional Periodic Boundary Condition (PBC) is used to generate the plane wave and the infinite meta-material.The simulations completed are as follows:1. By extracting the phase from simulated field pattern, the phase velocity in the slab meta-material is obtained precisely.2. The refractive ray from the interface between meta-material and the air is simulated.3. The refractive index of meta-material is calculated by measuring the phase velocity in the slab model and by measuring the direction of wave front leaving the interface between the meta-material and the air. The results from these two methods are in good agreement.4. The frequency ranges within which both the effective permeability and permittivity are negative are studied.5. The wave propagation in meta-material cylinder with a line source in its center is simulated.Another meta-material based on LC model is introduced briefly. The application and development of meta-material are introduced as well.
Keywords/Search Tags:meta-material, FDTD, negative index of refraction, negative permittivity, negative permeability, split ring resonator
PDF Full Text Request
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