A Memory Saving Augmented EFIE With Modified Basis Functions for Low-Frequency Problems

A new augmented electric field integral equation (A-EFIE) formulation is discussed in the low frequency. In the new formulation, both the electric current and charge are considered as unknowns. Different from the conventional A-EFIE, a constraint on the normal component of the magnetic field is added to modifying the formulation of A-EFIE for improving the accuracy and a kind of constant nodal functions is introduced for expanding the electric charge. With the proposed method, besides avoiding the low-frequency breakdown, the storage of impedance matrix is reduced over 35% compared with the conventional A-EFIE, which is owing to the application of constant nodal functions associated with vertices. Numerical examples illuminate the validity and performance of the new A-EFIE with constant nodal functions.