Estimations of radiation characteristics of an off-focus feed shaped dielectric lens antenna by a ray tracing method

Millimeter waves are planned for use in the near future in next generation mobile communication systems and ITS services. In this paper, a ray tracing method is employed to estimate the radiation characteristics. In the case of a shaped lens, the lens surfaces are given by numerical discrete data. So, it becomes rather difficult to find adequate refraction positions on the lens surfaces. By utilizing formulas of refracted rays and searching procedures of adequate refraction positions of the lens surfaces, ray tracings are achieved. Aperture phase distributions for various off-focus feeds are calculated. The beam shift characteristics are also calculated. Through numerical results, the accuracy of the developed estimation method are ensured.