Application of higher-order FEM elements to the analysis of microstrip structures

Microstrip structures, formed by metal traces printed on a dielectric substrate above a reference plane, are frequently the object of electromagnetic modeling. In this paper, hybrid FEM/MoM formulations employing conventional Whitney elements and newly developed linear-tangent/linear-normal (LT/LN) tangential vector finite elements (TVFEs) are applied to the analysis of microstrip structures with thin traces. This paper shows that the variation of the electric field below the trace is a significant issue to be addressed in microstrip structure modeling. Different mesh methods are investigated and the advantages of the LT/LN TVFEs are discussed.