Theory and Design of Medium Gain Dielectric Antennas

Double application of the Kirchhoff-Huygens-vector formula facilitates computation of the far field radiation pattern of dielectric antennas with rotational symmetry excited by cylindrical waveguides within practical computing times. In this paper special attention will be given to the near field expressions at the surface of the dielectric body, when higher order modes can propagate in the waveguide. These near field expressions allow a more analytical approach for the far field expressions. In designing medium gain dielectric antennas it would appear that the front of the dielectric works approximately like a lens and simple optical relations may be used for derivation of the curvature of the dielectric body. This computational method has formed the basis for designing a dielectric antenna with properties similar to those of a corrugated horn.