Hybrid finite element methods for conformal antenna simulations

Since the first publication of the paper by Silvester in 1969, the finite element method has enjoyed a strong interest for electromagnetic analysis. In fact, we can safely state that over the past 10 years, the greatest progress in computational electromagnetics has been on the development and application of partial differential equation (PDE) methods such as the finite difference-time domain and finite element (FEM) methods, including hybridizations of these with integral equation and high frequency techniques. The major reasons for the increasing reliance on PDE methods stem from their inherent geometrical adaptability, low O(N) memory demand and their capability to model heterogeneous (isotropic or anisotropic) geometries. These attributes are essential in developing general-purpose codes for electromagnetic analysis/design, including antenna design and characterization. At the University of Michigan we have developed a variety of hybrid finite element implementations which vary in capability from very fast and specialized to general-purpose codes for antennas analysis. Typical complexity of the antenna geometries is depicted and some specific applications are discussed.