Towards a Self-Adaptive Frequency Normalization Scheme for the Low-Frequency Stabilized Magnetic Field Integral Equation

Low-frequency preconditioned boundary integral equations based on quasi-Helmholtz decompositions are widely used to obtain the radiated or scattered fields by a finite structure over a wide frequency range. Specifically, for perfectly electrically conducting (PEC) structures, the conformingly discretized magnetic field integral equation (MFIE) plays a crucial role. However, a careful analysis and, potentially, ad-hoc adaptions are necessary for each excitation to ensure that all fields are obtained accurately. To avoid such cumbersome analyses, we propose an excitation agnostic and self-adaptive frequency normalization scheme. To this end, the appropriate scaling factors are derived based on the norms of the right-hand side (RHS) components without requiring any ad-hoc adaptions or any a-priori knowledge about the excitation. Numerical results demonstrate the effectiveness of this approach to obtain accurate fields.