Numerical study of surface integral formulations for low-contrast objects

Several surface integral formulations for electromagnetic interactions with homogeneous material bodies are studied numerically. Included are the well-known Muller and Poggio, Miller, Chang, Harrington, Wu, and Tsai (PMCHWT) formulations and two other formulations. One of the two formulations introduced gives a simple form of the Neumann series for low-contrast material bodies. The integral formulations are discretized into the matrix equations using the method of moments (MoM). The condition numbers of the matrices are evaluated using three definitions of norms and are shown as functions of combination constants. Numerical results also show the regions of the combination constants producing accurate results.