微波工程中的协同计算技术研究

Based on the applicant’s previous research works and to overcome the limitation of the current loosely-coupled and single-layer collaborative calculation in the microwave engineering, this project dedicates to develop a tightly-coupled and multi-layer collaborative calculation. Key technologies, such as the method of merging multi-algorithms’ equations to build a tightly-coupled and uniform equation system (i.e. the tightly-coupled collaborative calculation), the numerical algorithm to effectively solve the equation system, and the parallel computation will be deeply studied. Two microwave systems (i.e. a hybrid system consisting of an antenna and a circuit, and a cavity system containing nonlinear semiconductors ) will be presented as samples. The proposed collaborative calculation will perform on three layers from semiconductors, circuits to microwave systems: firstly obtaining the microwave effect on nonlinear semiconductors by employing a multi-physics calculation that includes the electromagnetics, semiconductor physics and thermodynamics; then extending the microwave effect modeling from semiconductors to circuits by incorporating the multi-physics calculation into an equivalent-model based circuit simulation; finally modeling the antenna and the cavity making use of an numerical electromagnetic simulation, and by an collaborative calculation that combines the electromagnetic simulation with the circuit modeling, so as to realize the modeling of the two microwave systems. In light of most current parallel computation systems adopt multi-core CPUs, this projects will make research on a multi-node and multi-core hybrid parallel computation technology to greatly improve the efficiency of the proposed collaborative calculation. A serial of experiments will be conducted to validate the collaborative calculation. This project will advance the collaborative calculation and its practical application in the microwave engineering, and moreover provide an effective tool to deal with a large number of problems that are unable or difficult to be solved by only employing one algorithm.

在前期研究基础上，克服目前微波工程中松散和单层次协同计算的局限，发展紧耦合和多层次协同计算技术。深入地研究协同计算关键技术，包括：融合多种算法方程以构建协同计算方程组（即紧耦合协同计算）、数值求解和并行计算等。研究并通过元件、电路和系统三级层次协同计算，实现对两类典型微波系统（天线和电路混合系统、包含非线性半导体元件的腔体系统）的计算和分析。利用电磁场、半导体物理和热力学的多物理场协同计算获取非线性半导体元件微波效应；采用多物理场和基于等效模型电路仿真的协同将计算从元件扩展到电路；电磁场仿真天线和腔体系统，并与电路效应计算相协同实现对微波系统的计算和分析。针对并行计算机采用多核CPU的现状，研究多核和多节点混合并行计算技术，大幅提高协同计算效率。开展验证性实验以检验协同计算的正确性。本项目研究将推动协同计算技术发展，为微波工程中大量单一算法不能或难以完成的计算难题提供有效的计算和分析手段。

本项目针对微波系统电磁效应的多物理协同计算开展研究工作，按计划完成了全部研究内容。在前期对元器件和电路两级层次多物理场协同计算研究基础上，研究并发展了系统级多物理场协同算法。完成的研究内容和取得的研究成果主要包括：. 对前期提出的半导体器件和电路微波效应协同算法进行了全面梳理，优化了计算公式和改进了计算流程，多物理场协同计算的效率和准确性得以提高，并增加了对半导体器件雪崩击穿等效应现象的计算和分析能力；开展针对由电路和电磁环境（包含空间电磁能量辐射和传播、金属或介质封装、线缆和孔缝等电磁能量通道等）组成电磁系统的多物理场协同计算研究，推导了完整的系统级多物理场协同算法公式，从而将多物理场计算从元器件、电路层次发展到电磁系统层次；对系统级多物理场协同计算关键技术：等效源及其加载技术进行了深入研究，推导了基于等效电流源、等效电压源，以及线、面、体三种结构模型加载技术的多物理场协同算法公式，通过典型算例分析了它们对多物理场协同计算准确性的影响；开展并完成多节点和多核混合并行计算的关键技术研究，包括构建集群并行计算机系统和基于Winsock的多节点和多核混合并行计算技术，大幅度提升了多物理场协同计算效率；项目针对两类典型微波系统（天线和电路混合系统、包含非线性半导体元件的腔体系统）开展了微波效应多物理场协同计算和验证性实验，完成的计算和实验包括：集总匹配电路加载微带双频耦极子天线、半封闭腔体中微带限幅器电路的空间电磁波辐射效应、兼具空间滤波和限幅特性的非线性频率选择表面等，通过计算和实验结果的对比和分析，充分检验了本项目所发展的多物理场协同计算的正确性。. 本项目在Applied Physics Letters、IEEE Trans. on Microwave Theory and Techniques等国际和国内学术刊物上发表学术论文12篇，SCI收录7篇，EI收录3篇。培养了12名博士和硕士高端人才。本项目完成了预定研究任务，推动了多物理场协同计算技术的发展，并为研究高功率微波作用下半导体器件和电路效应提供了有效和准确的分析和计算手段。