A fast algorithm based on volume integral equation for analysis of arbitrarily shaped dielectric radomes

The volume integral equation (VIE) combined with the multilevel fast multipole algorithm (MLFMA) is applied to analyze antenna radiation in the presence of dielectric radomes. In solving the VIE, the radome is modeled by small volume cells of tetrahedron or hexahedron shape so that three-dimensional (3-D) complex radomes can be modeled accurately. When the induced volume current is determined by the method of moments, the total radiation is calculated by adding the induced current radiation to that of the antenna in the absence of the radome. The application of MLFMA reduced the computational complexity to a lower order and hence electrically large-sized radomes are analyzed. Numerical results are compared with the analytical solution for spherical shells with dipole array as excitations. The radiation patterns of dipole arrays in the presence of ogive, cone, and hemisphere radomes are also presented.