A Resonant Extraction Method for Installed Antenna Radiation Calculations

In the calculation of the radiation patterns of antennas installed on complex structures using iterative solvers, the convergence rate is often slower compared to the problem with the structure alone without antenna. This is due to the resonant nature of the antenna. To increase the convergence rate, a resonant extraction method is introduced by which a small region including the antenna and its nearby neighborhood is singled out from the overall structure and treated using a direct method, and a reduced system is better conditioned, hence much less iteration numbers are needed if solved by an iterative solver. Numerical examples are provided to demonstrate the effectiveness of this method.