For the error of propagation constants with adopting the classical skin-effect model for the conductivity of normal metals in Terahertz frequency
a general and rigorous characteristic equation formulation is proposed for the analysis of hollow metallic waveguide. The characteristic equation for propagation constants is derived in terms of the field components equations and the boundary conditions in the circular waveguide. The propagation constants are obtained with the numerical solutions of the characteristic equation with the classical relaxation-effect model for the conductivity. The proposed method improves the accuracy for the full-wave characterization of waveguide performance
compared with the classical microwave approach that is the variational method with the classical skin-effect model for the conductivity. A comparison with the traditional variational method shows that the relative error of attenuation constant from the proposed method is reduced about 66% at 10 THz.
while a comparison with the skin effect model for conductivity shows that the relative error of attenuation constant using characteristic equation method can be reduced by 31% at 6 THz with the classical relaxation model.
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references
MITROFANOV O, JAMES R, FERNANDEZ F A, et al. Reducing transmission losses in hollow THz waveguide [J]. IEEE Transactions on Terahertz Science and Technology, 2011, l(1):124-132.
JAMISON S P, MCGOWAN R W, GRISCHKOWSKY D. Single-mode waveguide propagation and reshaping of sub-ps terahertz pulses in sapphire fibers [J]. Applied Physics Letters, 2000, 76(15): 1987-1989.
JEON T I, GRISCHKOWSKY D. Direct optoelectronic generation and detection of sub-ps-electrical pulses on sub-mm-coaxial transmission lines [J]. Applied Physics Letters, 2004, 85(25): 6092-6094.
ZHOU Yun, LUCYSZYN S. HFSS modelling anomalies with THz metal-pipe rectangular waveguide structures at room temperature [EB/OL]. [2011-09-12]. http:∥www.piers.org/piersonline/piers.php?volume=5number=3page=201.
MITROFANOV O, TAN T, MARK P R, et al. Waveguide mode imaging and dispersion analysis with terahertz near-field microscopy[J]. Applied Physics Letters, 2009, 94(17): 171104.1-171104.3.
TAN Xiaoling, GENG Youfu, ZHOU Jun, et al. Theoretical and experimental study on transmission properties of THz wave in metal-coated hollow waveguide[J]. Acta Physica Sinica, 2011, 60(5): 054101.1-054101.5.
FENG Guozhu, YANG Huajun. Optics nature of free electron model of metal and simulation [J]. Journal of Southwest University for Nationality, 2005, 31(2): 217-221.
COLLIN R E. Field theory of guide waves [M]. New York, USA: McGraw-Hill, 1960:182-195.
LIU Yuanping, HUANG BInke, JIANG Wanshun, et al. Effects of the coated lossy layer on the propagation characteristic of electromagnetic wave in a metal cylindrical waveguide [J]. Journal of Xi'an Jiaotong University, 2009,43(10):76-80.
STRATTON J A. Electromagnetic theory [M]. New York,USA: McGraw-Hill, 1941:526-530.
ROVETTA D, BOSISIO A V. Propagation constant of HE11 mode near the cutoff frequency in a circular waveguide [J]. IEEE Microwave and Wireless Components Letters, 2006, 16(5): 314-316.
MITROFANOV O, JAMES A H. Dielectric-lined cylindrical metallic THz waveguides: mode structure and dispersion [J]. Optics Express, 2010, 18(3): 1898-1903.
HASHIMOTO K. Circular TE0n mode filters for guided millimeter-wave transmission [J]. IEEE Transactions on Microwave Theory and Techniques, 1976, 24(1):25-31.