Metamaterial Effective Media Theory And Application In Antenna

At present, metamaterial has garnered considerable attentions all over the world dueing to the enormous potential of its basic theory and practical application. This paper studied metamaterial effective media theory and its application in antenna.On the basis of the works of the working group, a rigorous analysis of bianisotropic split ring resonator (SRR) metamaterial is presented for different electromagnetic field polarization and propagation directions. An alternative physical explanation for SRR resonance band gaps is gained by revealing the fact that imaginary wave number leads to the SRR resonance. Shown the SRR metamaterial resonance by FEM (Finite Element Method), and compared the conclusions of analytical method and full-wave analysis.Then, the author studied existing metamaterial parameter retrieval methods. The Smith's parameter retrieval method is then extended to Floquet mode analysis, and the S parameters from the two methods are compared. The resonance of SRR with different orientation is investigated to testify the proposed analysis. Compared with traditional methods, parameter retrieval method based on Floquet mode analysis reduces greatly the time to calculate the S parameters, thus it is more convenient for the analysis of metamaterial bianisotopic effects.Metamaterial ground plane is introduced to planar inverted-F antenna (PIFA) design to explore the potentially improved radiation. Through replacing the conventional capacitance by a metamaterial resonance circuit, the modified PIFA transmission line model physically interprets the unconventional properties. As is shown, such metamaterial PIFA exhibits a -10dB return loss of more than 100% bandwidth with resonance covering all wireless local area network applications and broadband wireless access form 2 GHz to 6 GHz. Nearly omnidirectional radiation pattern will be achieved at 2.4/2.5 GHz, but mainly backward radiation will be obtained at 3.8GHz and 5.1-5.8GHz.