Study Of Tri-band Frequency Reconfigurable Antenna And Design Of Control Circuits

With the rapid development of modern electronic devices and wireless communication technology, the requirements of the size and function of electronic equipments are more and more diverse. As the explosive growth of data, the need of broadband, high transfer rate, small volume is higher than before both in the field of national defense or civilian products. For the past years there are some shortcomings in wireless receiver and wireless transmission equipments among wireless systems. As reconfigurable technologies are coming into being, it has become a research hotspot. The reconfigurable technology is mainly used in the field of antenna which is the main component of wireless communications and the EBG structure. Due to the rapid development of PCB technology, the printed antenna and EBG structure can integrate with the subsequent control circuits seamlessly and easily. Reconfigurable antennas and EBG structures have also gotten more attention than ever. But there are some difficulties in the design of reconfigurable antenna and reconfigurable EBG structure. The thesis focuses on the control circuit design for reconfigurable antennas and reconfigurable EBG structures.First, this thesis introduces the basic theories and the important characteristics of reconfigurable antennas, and highlights on the significant performance of frequency reconfigurable antennas. Then we introduce the basic structure of EBG and explain how to combine EBG structures with man-made electrical control devices to form a reconfigurable EBG structure.Second, this thesis describes the design of tri-band reconfigurable antenna and bias control circuit theory. The detailed design steps of control circuits for the tri-band reconfigurable antennas is given. In this way it can protect the antenna device from man-made damage. Then theoretical analysis and design of controlling circuit for 128 elements array have been given.Third, we design the three-layer structure containing reconfigurable EBG structure and its bias control circuits. We also design the multiple programmable output voltage control circuit to meet the need of reconfigurable EBG structure to solve the man control problems of reconfigurable EBG structures.Final, as coming to the problem of three frequency reconfigurable printed antenna on-off ratio, we design the tri-band filter reconfigurable antennas structure which integrated three frequency reconfigurable microstrip filter structures and reconfigurable antenna, which greatly improves the reconfigurable antenna on-off ratio and has small influence on the characteristics of reconfigurable antennas.