Design and Application of Phased Array System

Since its invention, phased array has been extensively applied in both military and civil areas. The applications include target detecting and tracking, space probe communication, broadcasting, human-machine interfaces, and remote sensing. Although the phased array applications show a broad range of potential market, there are some limitations of phased array's development: high cost, complex structure, narrow bandwidth, and high power consumption. Therefore, novel ideas are needed to reduce these constraints. In this thesis, several new approaches about the design and application of phased array are presents. First, the principle of phased array and fundamental design equations are introduced. Second, a new application of phased array antenna for radar respiration measurement is presented. By integrating a 4×4 Butler matrix with four-element antenna array, there will be four distinct main beams in radiation pattern. This new approach can improve the measurement accuracy and realize a high detecting rate. Third, a compact phased array antenna system based on dual-band operations is introduced. Dual-band function can make N-antenna system obtain 2N unique radiation beams (N is an integer) and achieve a significant size reduction compared to the conventional single-band system. To verify the design concept, a four-element phased array antenna working at 5GHz and 8GHz is designed and fabricated. The measurement results make a good agreement with the simulations. Finally, a novel architecture of steering phase feeding network by using bi-directional series-fed topology is presented. This bi-directional series-fed network needs less phase shifters and realizes steering phase function by applying control voltage. ii ACKNOWLEDGEMENTS I would like to express the deepest appreciation to my major professor Dr. Hualiang Zhang, who has the attitude and the substance of a genius: he continually and convincingly conveyed a spirit of adventure in regard to knowledge and research, and an excitement in regard to teaching. His expertise in RF and microwave region improved my research skills and prepared me for future challenges. Without Dr. Zhang's guidance and persistent help, this thesis would not have been possible. I would like to thank my thesis committee members, Professor Hyoung Soo Kim and Professor Shengli Fu for their helpful suggestions and comments during my study. In addition, I am grateful to Professor Changzhi Li of Texas Tech University for providing his technology and support to my research. I want to thank all of my lab mates for their help, support, and cooperation. Finally, I want to express thanks to my family, …