Study On FDTD Method For The Propagation Characteristic Of Terahertz Wave

In this thesis, the method of Finite-Difference Time-Domain (FDTD) is applied to study the propagation characteristics of the Terahertz wave. The following works have mainly been done. Surface impedance boundary conditions in time domain are derived and applied in Finite-Difference Time-Domain method instead of modeling in lossy media straightly which reducing the solution space and producing significant computational savings. The propagation in lossy media of THz wave is looked as a problem of half-space. SIBC-FDTD method is used to analyze the reflection characteristics at the interfaces of lossy media in THz frequency. Then the influences of electromagnetic parameters are discussed. The principles of plasma stealth technology and ultra-wide band THz radar are introduced. The method of piecewise linear recursive convolution (PLRC)-FDTD is derived, and used to analyze the characteristics of THz wave propagate in the plasma which the distributing of electron density are uniformity,linearity and parabola. Then, the return attenuation characteristics of THz wave propagate in the conductor slab which is coated by plasma are studied. Finally, the FDTD method for periodic structure is introduced, and the periodic boundary condition and the total-field boundary are derived. The clothings structure of common and radiation protection are given in this paper. The characteristics of THz wave propagate in fibre structure of silver,clothings of common fibre and clothings of radiation protection are analyzed by FDTD method.