On Next Generation Broadband Wireless Mobile Communication Base Station Antenna Technologies

In the last40years, the wireless mobile communications industry has experienced rapid development. With the gradual maturity of3G technology, IMT-Advanced is becoming a hot spot in wireless communication area. In order to enable our country to gain a leading position in future communications standard development, it is necessary to study base station hardware which can meet the requirements of IMT-Advance system. As a signal transmitter or receiver, antennas for IMT-Advance system are being required to satisfy higher requirements due to its important role in wireless mobile communication system. The main work of this thesis is just to study the broadband base station antennas for next generation wireless mobile communication system. The main contents of this thesis are as follows:Firstly, the history of development of the mobile communication system and the significance of studies on next-generation mobile communication system are presented, and the basic requirements on base station antenna of IMT-Advanced are also summarized.Secondly, the basic antenna theory and concepts are briefly described, including some important antenna characteristics, the classification, beam forming, and installation methods of the base station antenna, etc.Thirdly, patch antenna is selected as the element of base station antenna array due to the limitations on the size of base station antennas. A multilayer aperture coupled patch antenna is used to meet the requirement of broad return loss bandwidth for IMT-Advanced system. The simulated and measured results show that the performance of the antenna element is suitable for the design of broadband base station antenna arrays.Fourthly, the relevant power splitter used in IMT-Advanced antenna system is also designed in this thesis. By using Wilkinson power divider as the prototype, we designed three types of power splitters, including1-to-2,1-to-3and1-to-4. All the types of splitters are fabricated and measured.Fifthly, a10-element linear array is designed based on the previously designed microstrip patch antenna element. To meet the requirement of horizontal beam width, the shape of the ground plane was carefully designed. The measured results of the linear array are in consistent with the simulated results and are able to meet the design requirements.Finally, based on DE algorithm, some studies on the beam forming of base station antenna arrays are carried out. The studies show that the beam forming of base station antenna arrays can be perfectly realized by using the DE algorithm.