Study On Theory And Method About The Measurement Of Metamaterials

Metamaterials is a kind of artificial composite materials, of which electromagnetic spectrum depends on the microstructure of the materials instead of constituent materials. Metamaterials performs better than other traditional materials in controlling electromagnetic wave, owing to its excellent physical prosperities. Coaxial cable, an important medium in transmission of electromagnetic wave, has been widely applied in variety of fields. In this paper, we study and analyze the exterior cloak and test system of coaxial cable based on the S parameter retrieval method.The research background of metamaterials and its developing history are all introduced in this paper, as well as its physical properties and implementation. Also, the principle of the realization of invisibility is explained. Then some knowledge about the coaxial cable and transmission characteristics are described.In this paper, we designed and implemented an external cloak based on the theory of transformation optics. Because it is not easy to obtain electromagnetic parameter of metamaterials by analysis method, we use S parameter retrieval method to analyze its electromagnetic properties. The paper makes use of emitter follower and vector-net analyzer to improve the test circuit for external cloak. In what follows, we make research based on simulation software, and compares experimental result with the simulation one.By studying the coaxial cable test system, we prove that it is valid to analyze the medium’s electromagnetic properties by S parameter retrieval method. By means of this method, as well as comparison between experimental data and theoretical values, we obtained the errors of electromagnetic parameters of dielectric ring in different conditions, which provides a reference for the error of data in following experiments.Our research signifies that S parameter retrieval method have significant advantages, such as easy in operation and realization, in testing of the properties of metamaterials. This method will play a more and more important role in the future with the development of metamaterials device.