Antenna Modeling Using an Iterative Absorbing Boundary Condition and High-Order Finite Elements

The iterative absorbing boundary condition (IABC) is a flexible and accurate way of truncating the computational domain for finite-element analysis of electromagnetic wave scattering, particularly when the element orders are adjusted carefully to minimize overall computational cost. The method is here extended to antenna problems, taking into account the feed modeling. Discretization and boundary errors in the feed reflection coefficient or in the radiated field are balanced during the iteration. Results for a waveguide terminated in a flange, a horn antenna, and a microstrip patch antenna demonstrate the accuracy of the approach, and the computational savings relative to the use of the same element order during the whole iteration.