电磁多尺度和非线性效应分析

微观尺度上的结构和电接触特性对于宏观尺度上的电磁特性具有重要的影响.针对多尺度结构的非线性无源互调(PIM)无法用频域方法直接计算的问题,提出了基于Floquet理论的全波方法,对具有周期性微观结构的多尺度电大尺寸问题进行计算,从而准确地计算其电特性.此外,将产生非线性的金属结的等效电路模型引入到全波分析方法中,通过全波方法与等效电路方法相结合的方式来分析多尺度结构的无源互调问题.数值计算结果表明该方法可以有效地评估微观结构对于宏观结构电性能的影响,并解决了时域方法求解电大尺寸微波部件产生的计算累积误差较大这一难题. 

Analysis of electromagnetic multi-scale structure and non-linear effects

The microstructures and the electrical contact property may affect the performance of the macro scale objects, and the passive intermodulation (PIM) problems cannot be directly calculated by frequency-domain methods. Firstly, the Floquet's theorem combined with the full-wave method was proposed to analyze the electrical performance of the multi-scale structure with periodic microstructures. Secondly, an equivalent circuit model of non-linear metallic junctions coupled with full-wave frequency domain method was adopted to analyze the PIM problems of multi-scale structure. The numerical results show that the method proposed can evaluate the influence of microstructure on the performance of macrostructure, and eliminate the accumulation of computational error appeared in the time domain method which is unacceptable in electrically large objects.