多尺度粗糙度对波导传输性能的影响  

Effect of Multi-scale Roughness on Transmission Performance of Waveguide

作　　者：李娜[1] 

机构地区：[1]西安电子科技大学电子装备结构设计教育部重点实验室,陕西西安710071

出　　处：《电子机械工程》2012年第1期21-25,32,共6页Electro-Mechanical Engineering

基　　金：中央高校基本科研业务经费资助项目(JY10000904019)

摘　　要：文中针对波导内壁存在的粗糙度对波导传输性能的影响问题进行了建模、仿真研究。首先,基于改进的二维分形函数,建立了波导内壁粗糙度的多尺度数学模型。基于此模型,以数值积分和有限元法为数学工具,分别推导出了考虑粗糙度影响的波导内壁局部和整体的功率损耗公式。作为对理论结果的验证,进行了一个针对矩形波导的仿真实验。分别将二维分形函数、多尺度粗糙度模型和三角波作为粗糙度的模拟函数,将得到的功率损耗结果与用经典文献中提供的计算方法得到的结果进行对比,结果表明本文所建立的多尺度粗糙度模型的结果在高频时更接近经典文献数据。随后,又对多尺度粗糙度模型的两个主要参数对功率损耗的影响程度进行了对比,结果显示粗糙度表面密度对功率损耗的影响较小,而分维数的影响较大。随着表面粗糙度均方根值的增大,功率损耗的比值也逐渐增加,最大值可达光滑表面功率损耗的1.8倍。A model and simulation research about the effect of multi-scale roughness in waveguide inner surface on transmission performance of waveguide was presented in this paper.Firstly,the multi-scale roughness of the waveguide was simulated by an improved two-dimensional fractal function.Based on the model,using numerical integration and finite element method as mathematical tools,two approximate formulas were deduced to calculate the power dissipation of local and global roughness respectively.As verification,a simulation experiment using a rectangle waveguide was carried out.Comparison of the result attained by two-dimensional fractal function,multi-scale roughness model and the triangle with the result of Morgan theory was made and it indicates that the result of the multi-scale roughness model is more close to that of Morgan theory in high working frequency.In addition,we found that the surface density of roughness has little influence on power dissipation,while the influence of fractal dimension is very strong.With the increasing of MSR value of surface roughness,the power dissipation of rough surface increases and the maximum value is 1.8 times larger than that of smooth surface.

关 键 词：表面粗糙度 多尺度模型 二维分形函数 功率损耗 有限元方法 矩形波导 

分 类 号：TN814[电子电信—信息与通信工程]