A New Type of Macro-Elements for Efficient Two-Dimensional FEM Analysis

This letter deals with a model order reduction technique applicable for driven and eigenvalue problems solved using the finite element method (FEM). It allows one to efficiently compute electromagnetic parameters of structures comprising small features that require strong local mesh refinement. The subdomains of very fine mesh are separated from the global domain as so called macro-elements that undergo model reduction. The macro-elements of reduced order are described by a significantly smaller number of unknowns, thus improving overall simulation speed. In addition, we present an algorithm of macro-elements multiple reuse, called cloning, which provides further decrease of the computation time and memory requirements. The results of the two numerical experiments, in which the local mesh refinement exceeds the factor of 400, illustrate the properties of the proposed methodology and prove that it increases the FEM efficiency significantly and is particularly suitable for multiscale problems with strong variations of desired mesh density.