PYI: Toward The Realistic Modeling of Electromagnetic Scattering Problems

PI对他在总统青年调查人员奖下的工作描述如下：在制定电磁散射问题时，人们经常被迫在两个相互冲突的要求之间做出选择：严格的分析和现实的建模。在过去，人们过于强调严谨的分析，而忽视了逼真的建模。最近，出现了几类问题，其中几何形状对散射特性的影响是最重要的。这项研究将解决两个这样的问题：(1)部分开放空腔的雷达截面分析。将喷气发动机进气口的雷达回波降至最低是隐身技术的主要挑战之一。将应用一种新的射线发射技术来分析进气内壁成形或涂层的效果。(2)微带不连续性的表征。在微波单片集成电路设计中，微带传输结构的准确电磁特性是必不可少的。为了提取对CAD工具开发至关重要的散射参数/电路模型，将对各种不连续面应用一种时域有限差分方法。该PYI奖将研究电磁散射的理论建模问题。重点将放在现实的建模方法上，其中散射体的几何形状是最重要的。重点将放在分析(1)喷气发动机进气口等部分开放腔体的雷达截面，以及(2)微带不连续性的特征，这对开发单片微波集成电路的计算机辅助设计工具是很重要的。

The PI describes his work under the Presidential Young Investigators award as follows: In formulating electromagnetic scattering problems, one is often forced to choose between tow conflicting requirements: rigorous analysis vs. realistic modelling. In the past, much emphasis has been placed on the rigorous analysis at the expense of realistic modelling. More recently, several classes of problems have arisen in which the effect of the geometry on the scattering characteristics is of prime importance. Two such problems will be addressed in this study: (1) Radar cross section analysis of partially open cavities. Minimizing radar returns from jet engine intakes is one of the major challenges in stealth technology. A novel ray launching technique will be applied to analyze the effect of shaping or coating the intake interior. (2) Characterization of microstrip discontinuities. Accurate electromagnetic characterization of microstrip transmission structures is essential in the design of monolithic microwave integrated circuits. A time-domain finite- difference approach will be applied to various discontinuities in order to extract scattering parameters/circuit models crucial to the development of CAD tools. This PYI award will study theoretical modelling problems in electromagnetic scattering. The emphasis will be on realistic modelling approaches in which the geometry of the scatterer is of prime importance. Areas of emphasis will be on analysis of (1) radar cross sections for partially open cavities such as in jet engine intakes, and (2) characterizations of microstrip discontinuities which are of importance in developing computer aided design tools for monolithic microwave integrated circuits.