【作者】 李强；

【导师】 郭立新；

【作者基本信息】 西安电子科技大学 ， 无线电物理， 2013， 硕士

【摘要】 电大尺寸复杂目标散射特征的测量往往受到昂贵的费用以及场地,环境的限制,通过测量缩比后模型的散射特性可以得到原型的散射特性。本文针对电磁系统中的若干缩比相似性条件展开了研究,主要工作如下:1.研究了无耗及有耗电磁系统的缩比条件,缩比可由电参数缩比和几何缩比构成。2.介绍了经典相似率,分析了海水介电常数随频率,温度以及盐度的变化。研究了微波波段介电特性的差异对反射、散射系数影响。3.介绍了随机粗糙面的统计参数,利用Monte Carlo方法模拟生成粗糙面的理论,重点讨论了一维、二维高斯粗糙表面和一维、二维PM海谱海面、二维JONSWAP海谱海面的几何缩比条件。4.计算了不同参数缩比条件下一维、二维高斯以及PM海谱粗糙面的散射截面。数值结果表明,本文给出的粗糙表面几何缩比条件是有效的。更多还原

【Abstract】 The measurements on scattering characteristics of large complex target is always restricted by expensive cost, venues and environment, and the scattering characteristics of the prototype can be obtained by measuring the scattering characteristics of the scaled model. Several scaled similar-conditions in electromagnetic systems are studied in this paper. The main works are as follows:1. The scale conditions of lossless and lossy electromagnetic systems is studied. It is found that scale includes electrical scale and geometrical scale.2. The classic similar rate is introduced, the dependence of requency, temperature and salinity on the permittivity of sea water are analyzed. The influence of dielectric properties on the reflection and scattering coefficient in the microwave band are examined.3. Random rough surface statistical parameters and rough surface model with the Monte Carlo method are introduced. Emphasis is put on studying, the geometric scale conditions of one-dimensional and two-dimensional Gauss rough surface, one-dimensional and two-dimensional PM spectrum sea surface, as well as two-dimensional JONSWAP sea surface are studied emphatically.4. The Radar Cross-Section(RCS) of one-dimensional and two-dimensional Gaussian, as well as the PM sea spectrum rough surface is calculated with different scale parameters. Numerical results show that the geometrical scale conditions of rough surface are effective.更多还原