| This thesis studies the secondary pattern of a perfectly conducting reflector antenna system being illuminated by an array feed with arbitrary location, polarization, and orientation. The methods of analysis used are physical optics (PO) and the application of the Fast Fourier Transform (FFT) to the aperture fields obtained using geometrical optics (GO), geometrical theory of diffraction (GTD) and a brute-force FFT. Key features of the present work are (i) the reflector surface is completely arbitrary, (ii) the incident field from the array feed is most general with arbitrary polarization and location, and (iii) the edge diffraction is calculated by either UAT (Lee and Deschamps)or by UTD (Kouyoumjian and Pathak).;The techniques developed for secondary pattern calculation have several applications. These applications are the strategy for calculating reflector antenna patterns and directivity optimization of a reflector antenna with cluster feeds, and reducing the sidelobe level of a reflector antenna by adding auxiliary reflectors. |
