Synthesis of Offset Dual Reflector Antennas Transforming a Given Feed Illumination Pattern Into a Specified Aperture Distribution

The problem of transforming a given primary feed pattern into a desired aperture field distribution through two reflections by an offset dual reflector system is investigated using the concepts of geometrical optics. A numerically rigorous solution for the reflector surfaces is developed. The solution gives an exact aperture phase distribution and an aperture amplitude distribution accurate to within some numerical tolerance. In a previous work, Galindo, Mittra and Cha {7} have addressed the same problem and have developed an approximate solution which is constructed via a two-step process. The first step consists of generating a solution on the basis of an ad hoc assumption on the mapping function which relates the two reflector surfaces. Next, the solution, thus obtained was corrected by keeping only the subreflector and synthesizing a new main reflector which exactly satisfies the requirement for the aperture phase distribution (but not the amplitude condition). In our synthesis method, we derive the solution for both of the reflector surfaces in a one-step process. However, this procedure does not always yield a smooth solution; i.e., the reflector surfaces may not be continuous or their slopes may vary too rapidly. In the event of nonexistence of a numerically rigorous smooth solution, an approximate solution that enforces the smoothness of the reflector surfaces can be obtained. In the approximate solution, the requirement for the aperture amplitude distribution is relaxed and the condition on the aperture phase distribution is continued to be exactly satisfied.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Hyjazie, Fayez Mohamed

• Engineering, Electronics and Electrical

Language dc:language

eng

Identifier

(UMI)AAI8026529

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/66231