A Review and Comparison of Some Asymptotic Techniques for Calculating the Wide-angle Radiation Pattern of Paraboloid Reflector Antennas

The paper starts with a review of calculation methods for determining the complete far-field radiation patterns of reflector antennas. Subsequently, a direct comparison is made between PO, APO, CAPO, GTD, UTD and EEC methods by applying all of these techniques to one and the same reflector antenna configuration. It is shown that both UTD, including surface-diffracted rays, and CAPO is satisfactory for calculating the scattered field from reflector antennas in wide-angle regions (away from the antenna axis). The correct results in both forward- and rear-axial region can be obtained with PO and EEC, respectively. Finally, special attention is paid to the transition angle between EEC and UTD.