Experimental Study On Microwave Left-handed Metamaterial

Left-handed material (LHM) is a newly discovered electromagnetic artificial metamaterial with simultaneously negative permittivity and permeability. Compared with tranditional materials, electromagnetic waves transmitted in such material will behave some fantastic phenomena, such as negative Snell refraction, reversed Dollper effect, reversed Cerenkov radition, and so on. The discovery of left-handed material has been regarded as one of the ten most significant discoveries in science community in 2003, and has been the front and focus area in Physis and Electromagnetics research. Focusing in the experimental study on the microwave left-handed material, this dissertation presents multiple researchs and improvements on the periodic metallic structures based left-handed material. Dissertation also presents some experimental and simulation studies on some potential applications of left-handed material. The original works and valuable results of this dissertation are as follows:1. A set of X-band automatic experiment platforms for the verification and measurement of left-handed properties with high efficiency and precision are established. Through power transmission, prism refraction and beam shifting experiments, various electromagnetic characteristics, such as refractive index, loss and S parameters, and various shaped left-handed material samples could be measured and verified between each other.2. The beam shifting experiment is designed and realized to further verify the LH properties. This experiment improves the prism experiment theoretically and hence gives more convincible experimental results. Anticipated results have obtained through this experiment for several reported and new constructed LHM samples.3. Several kinds of basic structures of left-handed material are analyzed and simulated. The procedure and methods for constructing new type microwave left-handed are summarized. By applying such approach, multiple new samples including the structures of symmetric rings, embedded rings, rings are desgined, realized and/or verified.4. A one-dimensional anisotropic LHM sample based on -like metallic patterns is realized for the first time. The experimental results indicate that, such sample has advantages of wide band, low loss and is easy to produce.5. By applying standard hot-press technics for the multiplayer PC boards manufacture, a solid-state, low-loss one-dimensional LHM sample based on -like metallic patterns is present. Experiments show that such sample is with the best characteristics in all the reported samples. The insertion loss is less than 0.5 dB per unit cell and the effective band is wider than 1 GHz. Such characteristics and the stable electronmagnetic and mechanical properties make it possible for it in the real applications, therefore has significant meanings.6. Discussions and preliminary experiments are given for some potential applications of left-handed materials. Experimental results which are in accordance with expects for the focusing of plane wave using symmetric rings and the focusing of radiate source using rings are obtained. Simulation results are also obtained concerning the -like structure based backward radiate antenna and transmission line based left-handed structures.