Abstract: When the electromagnetic scattering property of the body of revolution object is to be analyzed, the mode decomposition technique is usually adopted to alleviate the computational burden. The surface equivalent electric and magnetic currents calculated by this approach are made up of many mode components, so too much computing time will be spent if the far-field is calculated directly by integral operation due to the oscillation of the integrand. Based on the reciprocity theorem, this paper presents a fast calculation method of the far-field scattering from the rotationally symmetric object. By taking advantage of the exponential distribution property of the surface equivalent currents under each mode and the structural property, we deduce the analytical expressions for the integral with respect to the azimuthal angle, and thus the two-dimensional integral is reduced to the easily computed one-dimensional arc-length integral. Simulation results for a dielectric sphere irradiated by the plane wave indicate that it will take 212 seconds to calculate the far-field scattering if the 30-point Gaussian integration is used, while only less than 1 second is needed by our presented method under the same discreteness and computer hardware.

Key words: bodies of revolution, mode decomposition, reciprocity theorem, far-field scattering