【摘要】 建立了金属圆波导中电磁模式的特征方程,通过特征方程研究了涂敷层电导率和厚度对电磁波传播特性的影响规律.先从圆波导中电磁波满足的场方程及边界条件出发,推导了在波导壁电导率及厚度有限、内壁具有金属涂敷层时满足传播常数的圆波导特征方程,并得到了各模式传播常数的近似解析式.通过近似解析式和数值法求解特征方程,得出金属涂敷层的厚度及电导率对衰减常数及相位常数的影响规律,解析解与数值解的结果具有很好的一致性.研究结果表明,金属涂覆层厚度在小于2倍趋肤厚度时对电磁波传播特性影响最大,在大于3倍趋肤厚度时趋于稳定值.更多还原

【Abstract】 Based on the model of cylindrical waveguide coated with lossy conductor on its inner surface,the effects of the coated layer on the propagation characteristic of electromagnetic wave are studied.The characteristic equation is derived from the electromagnetic equation and boundary conditions under the assumption that both the conductivity and thickness of the coated layer and the waveguide wall are finite.Then the approximate analytic formulas for the propagation constants are obtained.Finally,the effects of the coated lossy layer on the propagation characteristic are presented.The approximate analytic results agree very well with the numerical solutions obtained by solving the characteristic equation.The results show that the lossy layer has a great effect on the propagation constants when the thickness is smaller than 2 times the skin depth of the lossy layer.更多还原