Computation of Characteristic Modes for Dielectric Bodies Using Volume Integral Equation and Interpolation

Characteristic mode analysis (CMA) provides useful insights for the analysis and design of dielectric bodies, such as dielectric resonator antennas (DRAs) and dielectric scatterers. In this letter, an interpolation method is proposed to reduce the computational burdens of volume integral equation based CMA. The CMA is performed at several discrete frequencies, and the eigencurrents and eigenvalues at intermediate frequencies are obtained using efficient polynomial interpolation. Selection of the polynomial is examined briefly. Homogeneous and inhomogeneous DRAs are computed and compared with verified results. This method reduces the computational time by about one magnitude according to the required frequency resolution.