Analysis of microstrip discontinuity by edge-based FEM combined with SOC technique

In this paper, the application of the edge-based vector finite-element method combined with the short-open calibration (SOC) technique to three-dimensional microstrip discontinuity is presented. This SOC technique is directly accommodated in the FEM algorithm, and is used to truncate the computational domain. The developed FEM algorithm is applied to the modeling of microstrip discontinuities that can be segmented into two distinct sections: a static model of feedlines, and a dynamic model of circuit discontinuity. The FEM is formulated in such a way that the port voltages and currents are explicitly represented through relevant network matrices. The SOC technique is used to remove or separate unwanted parasitic errors brought by the approximation of the impressed voltage source, and also to address the problem of the resulting consistency between different simulations. Truncation of the computational domain by the SOC technique for microstrip circuits makes the iterative solvers for large-sparse linear matrix equations from the FEM converge much faster than by perfectly matching layers (PMLs). Results for microstrip discontinuities are very well compared with available publications. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 169–174, 2001.