Modal analysis of spherical passive reflectors

A method for determining plane-wave scattering by spherical passive reflectors is outlined. The scattering from the passive reflector is determined in a two-step process. First, the desired field representation is expressed as a superposition of mode functions that are chosen in order to permit simple evaluation of the associated boundary conditions. This allows the plane-wave scattering from a capless reflector to be determined on the surface of the device. Afterwards, field equivalence is employed to determine the scattered far-field of the passive reflector. The analysis requires the expansion of a plane wave, electric current element and magnetic current element in terms of spherical wave functions. The approximation made is that the currents on the conductor are those dictated by physical optics. The results obtained are shown to compare well with experiment data.<>