Extensions to the hybrid method of moments/uniform GTD formulation for sources located close to a smooth convex surface

We present an extension to the uniform geometrical theory of diffraction (GTD) for reflection from smooth curved surfaces. This approach allows the source to be much closer to the reflecting surface than the conventional uniform GTD formulation and does not require a Hertzian dipole source. In essence, the field point is mirrored in the plane tangential to the specular (reflection) point; the incident field is then calculated at the mirror point and the uniform GTD reflection coefficients are used to mirror this field to the original field point. This formulation reduces exactly to the conventional uniform GTD if the incident field is ray optical. The application to a hybrid method of moments (MoM)/GTD code is outlined and results computed using this code are presented for a dipole radiating in the vicinity of a cylinder.