Analysis of spheroidal dielectric lens-array antenna

Field pattern of arrays radiating into Spheroidal dielectric lenses are expressed in terms of an exact spheroidal (SDL) modal expansion. Since the SDL Vector modes are not orthogonal, each the SDL modes are expressed in terms of a truncated sum of Spherical (SPL) vector modes, that exhibit orthogonality over a spherical measurement surface surrounding the lens and array. The matrix of SDL - SPL modal coefficients can be obtained by applying boundary condition on the lens surface. This can be used as a generator to express the field at any point on the near field surface. This field can be easily transformed to the far field using standard Spherical modal expansion or current integration. This technique has been applied to a 2×2 array at 10 GHz radiating into a SDL lens and the radiated fields computed with 20 SDL modes, with each SDL mode expressed as 20 SPL modes. The results are compared with a well-known EM flow solver.