الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The wireless communication technology has been witnessing a major development over the past few years. Antennas play a vital role in all types of wireless devices. Therefore, Antenna synthesis is the essential part of designing antenna systems to match the required radiation characteristics. Additionally, circular antenna arrays have a highly practical interest and it is adapted in many wireless communication systems for their ability of obtaining a good omnidirectional pattern, azimuth scanning, and beam steering. In this thesis, new synthesis algorithms of circular antenna arrays to achieve useful beamforming applications are presented. The proposed algorithms yield to provide new circular antenna arrays with new geometrical dimensions and excitation distributions. Synthesis of the circular antenna arrays was accomplished through analytical techniques and optimization techniques. The presented algorithms were able to achieve many important radiation pattern criteria such as beam shaping, controllable and fixed side lobes level, and minimize the number of antenna elements. The neumerical results showed that the desired and synthesized patterns are highly matched. Furthermore, we recommend to implement the synthesized CAA system using microstrip technology. The thesis introduces the implementation of a proposed circular antenna array system with reduced number of antenna elements using the CST Microwave Studio software package. The performance of the circular antenna arrays on the CST Microwave Studio software package is done using real antennas rather than isotropic antennas to approve the effectiveness of the proposed algorithm. This implementation provides an integrated study on the radiation pattern in terms of three-dimensional and polar representation of the pattern, measuring the gain and the efficiency of the pattern, observing the scattering parameters, and the geometrical structure of the antenna array. The implementation of the CAAs on the CST provides a satisfactory results which can be deployed in real antenna systems.