Slits in parabolic reflector antennas.

Diffraction by slits and scattering by antennas with slits in their reflectors are investigated. Attempts are made to engineer nulls in the rear radiation patterns of relatively small (ten wavelength) aperture reflector antennas by changing the size and position of slits in the reflectors. Diffraction by sharp edges are considered using a modified form of the Geometrical Theory of Diffraction and also reflector surface currents are studied from an integral equation standpoint via the Method of Moments and hybridised forms of the Method of Moments. Both amplitude and phase of electromagnetic fields are measured the use of a Microwave Homodyne Detection System, and experimental results are presented along with theoretical results