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A new surface integral equation formulation for scattering from perfectly conducting objects is presented. The formulation is developed by adding a constraint on the normal component of the magnetic field to the augmented electric field integral equation (AEFIE) and extracting the static charge solution. The resulting AEFIEnH-S formulation is discretized using the method of moments with Rao–Wilton–Glisson (RWG) source functions and Buffa–Christiansen (BC) test functions. An iterative diagonal matrix scaling algorithm is used to improve the conditioning of the discrete system. Numerical examples demonstrate that the AEFIEnH-S is stable and accurate as the frequency is reduced for closed, open, and multiscale multiply connected geometries. The formulation relies only on diagonal preconditioning, it accurately models the near electric, near magnetic, and far fields, it does not require frequency scaling of the unknowns, and it does not incorporate any type of Helmholtz decomposition. [ABSTRACT FROM PUBLISHER]

The properties of different forms of the combined field integral equation (CFIE) formulation of electromagnetic scattering from convex, perfect electrically conducting geometries are considered. Several difficulties encountered in the numerical implementation of the traditional CFIEs of electromagnetic scattering theory are discussed. An alternate form of the CFIE is introduced which is free of many of the deficiencies of traditional formulations for smooth, convex geometries. The improved numerical properties of the new formulation are illustrated with numerical examples. [ABSTRACT FROM AUTHOR]

A new version of the combined field integral equation (CFIE) is introduced for the formulation of time-harmonic electromagnetic wave interactions with perfect electric conductors (PECs). The new CFIE-hd formulation is obtained by imposing a Helmholtz decomposition of the current via appropriate surface integral equation constraints. Discretization is performed using a locally corrected Nyström method, and the performance of the resulting numerical scheme is examined for several PEC objects. It is observed that the proposed strategy is frequency stable, provides accurate solutions for the electric and magnetic fields from low to moderate frequencies, and eliminates false interior resonances. [ABSTRACT FROM PUBLISHER]

Localizing modes provide an effective basis for developing efficient, error-controlled factorizations of the dense matrices encountered in integral equation formulations of wave phenomena at low to moderate frequencies. An essential component of these factorization algorithms is the numerical determination of the underlying localizing modes. This communication describes the details of an efficient procedure for computing the so-called non-overlapping, localizing modes. The principle component of the procedure is a QR-like factorization of the sparse multilevel data structure used to compress discrete integral operators. Numerical examples demonstrate the performance of the algorithm. [ABSTRACT FROM AUTHOR]