High Frequency Improvements to PO-based Methods for the Analysis of Integrated Dielectric Lens Antennas

A high frequency approach is presented for evaluating the radiation pattern of integrated dielectric lens antennas. The method consists in refining the Physical Optics (PO) currents on the lens surface, by the inclusion of diffractive effects that emerge in correspondence of those angles of incidence which approach the critical angle associated to the dielectric -air contrast. Indeed, those rays from the source that impinge on the lens surface under critical angle of incidence excite lateral wave contributions and relevant transition field. The effect may be estimated by deriving a more accurate expression of the currents on the basis of the Green´s function of the dielectric half-space locally tangent at the actual lens surface. It will be shown that the proposed formulation provides strong deviations from the ordinary PO, while exhibits a good accuracy when compared by a full-wave MoM result.