The geometrical theory of diffraction applied to antenna pattern and impedance calculations

The geometrical theory of diffraction is applied to the calculation of the radiation pattern and impedance of a monopole antenna on a perfectly conducting circular ground plane of limited extent. In this calculation, the radiation problem is resolved into two components, one being the monopole contribution and one the edge contribution. The impedance problem is resolved into the components of a reflection from the monopole in an infinite ground plane and a reflection from the circular edge as seen through the antenna. The known solutions of these individual components then permit the calculation of the overall radiation pattern and impedance by superposition. The techniques described are general and are considered applicable to a large class of similar radiating structures.