Basic And Applying Research Of Metamaterial In Microwave Band

Metamaterial is a new type of artificial material or macroscopic composite having a manmade, three-dimensional, periodic cellular architecture designed to produce an unusual properties, which are not available in nature materials. Nowadays metamaterial researches focus on three major branches, which are left-handed materials, photonic crystals, and super magnetic materials. Electromagnetic researchers often use the term, quite narrowly, for left-handed material. Left-handed material is a kind of material, which has negative permittivity and permeability in some frequency range. This property leads to negative refractive index, negative Doppler shift, negative Cherenkov radiation and other related unusual phenomenon.Due to the special electromagnetic properties of metamaterial, it can be applied in a variety of wireless communication and national defense application such as miniaturization of microwave devices. Meanwhile negative refractive material created optical superlens which is capable of subwavelength imaging. According to the super characteristic of metamaterial mentioned above, American journal"Science"made it top ten science and technology breakthrough in 2003.This paper begins with the review of the history of metamaterials'development and the present status of metamaterial research both domestically and abroad. Second, the paper introduces the conception and characteristic of left-handed material and its three-dimensional designed structure. After showing the propagation theory of left-handed material clearly, the paper demonstrates LHM's application in microwave device step by step. This paper focuses on the parameter (permittivity and permeability) extraction method of homogeneous metamaterial based on the transmission line model. This method provides a solution to get the phase information through the [ABCD] matrix of transmission line port and then to extract the parameter of metamaterial. The paper also uses a numerical approach to prove rightness of the method and applies the method into the Split-Ring Resonator structure to extract the permeability.At last, the paper makes a deep analysis of propagation theory of a waveguide filled with SRR structure and waveguide miniaturization method. Two methods to explain the pass band of waveguide below its cutoff frequency are discussed and compared: transmission line method and longitudinal field method in uniaxial anisotropy homogeneous metamaterial.