球形微粒对电磁波的散射效应研究分析 电气工程专业VIP专享VIP免费

球形微粒对电磁波的散射效应研究摘要基于Mie散射理论，解析研究了带电水滴对电磁波的散射效应。首先概述矢量波动方程的解析求解方法和Mie散射理论，推导出平面波的矢量球函数展开式，给出球形微粒的散射场、散射系数以及散射矩阵的解析式。然后就电中性水滴和带电水滴展开讨论，分析比较电中性球形水滴的散射光强与散射角之间的关系，强调了前向散射的优势。采用MATLAB软件，计算对比了面电导率不同的带电球形水滴对电磁波的散射系数以及散射能量分布的差别。计算结果表明：面电荷使面电导率达到微西门子量级时，对电磁波的散射会产生明显的影响。随着面电导率的增加，散射的多瓣结构减弱，趋于均匀，但前向散射仍比较强烈，后向散射仍略强于侧散射。此外，散射系数会随面电导率的增加发生较大的变化，直到趋于定值。该论文有图4幅，表1个，参考文献35篇。关键词：Mie散射球形微粒散射强度电磁波散射StudyonScatteringofSphericalParticlesonElectromagneticWaveAbstractAccordingtothetheoryofMiescattering,wehavestudiedthescatteringofelectromagneticwavebyachargedwaterdroplet.Firstly,wehavesummarizedtheanalyticsolutionofvectorwaveequationandthetheoryofMiescattering.Wehavededucedtheexpressionofvectorsphericalharmonicoftheplanewave,andgiventheanalyticexpressionsofthescatteringfield,thescatteringcoefficientsandthescatteringmatrix.Thenwehavediscussedelectricallyneutralandchargedwaterdroplets.Wehaveanalyzedandcomparedscatteringintensityofaelectricallyneutralandsphericalwaterdroplet,withthescatteringangle,emphasizedtheadvantageoftheforwardscattering.ByuseofMATLAB,wehavecalculatedandcompareddifferenceofscatteringcoefficientsanddistributionofscatteringenergyofelectromagneticwavewithachargedsphericalwaterdropletofdifferentsurfaceconductivity.Theresultsshowthatwhenthesurfaceconductivityreachesmicroseconds,therewouldhaveagreateffectonthescatteringofelectromagneticwave.Withtheincreaseofthesurfaceconductivity,thelobesofscatteringwoulddecreaseandtendtobeuniform,buttheforwardscatteringisstillstrong,andtheback-scatteringisalsostrongerthanthesidescattering.Furthermore,thescatteringcoefficientswouldhaveabigchangewhenthesurfaceconductivityincreases,untilthecoefficientstendtobeconstant.KeyWords:Miescatteringsphericalparticlesscatteringintensityscatteringofelectromagneticwaves目录摘要..............................................................IAbstract...........................................................II图清单.............................................................IV表清单.............................................................IV1绪论..............................................................11.1球形微粒对电磁波散射的经典理论概述..........................11.2研究内容....................................................22矢量波动方程求解和平面波的矢量球函数展开式........................32.1矢量波动方程的求解..........................................32.2平面波的矢量球函数展开式....................................63球形微粒的散射参量................................................73.1球形微粒的内部场和散射场....................................73.2球形微粒的内场系数、和散射系数、....................83.3与散射角有关的函数和...................................93.4散射矩阵...................................................114水滴的散射性质...................................................144.1呈电中性的水滴.............................................144.2带电水滴...................................................165总结.................................