Research On ±45° Dual-polarized Omnidirectional Antenna

With the rapid development of wireless communication, customers demand for wideband and high data transfer rate of mobile business more and more. In recent years, WIMAX(Worldwide Interoperability for Microwave Access) system is becoming a hot topic of concerns. WIMAX is a wireless communication standard, also known as 802.16 wireless metropolitan area network. It can provide users within the scope of a few tens of kilometers of high-speed data transfer services. In a wireless communication system, antenna plays a very important role, which often determines the performance of the whole system. In order to achieve wide coverage and large channel capacity of WIMAX system, we need to design a dual-polarized omnidirectional antenna. In this thesis, we need to design a ±45° dual-polarized omnidirectional antenna at specified frequency.Among linear-polarized antenna in existence, vertical/horizontal antennas can realize omnidirectional pattern, ±45° dual-polarized antennas can only realize sector pattern instead of omnidirectional pattern. Therefore, this article puts forward ±45° dual-polarized omnidirectional antenna fills the blank of related research, this is an innovation point.The main contribution of this paper is summarized in the following areas:(1) In order to increase the channel capacity and achieve higher diversity gain, antenna array using microstrip antenna as element can meet the both requirements of ±45° dual polarization and omnidirectional pattern at the same time.(2) Introduced the specific antenna structure and how to array the antenna elements and the simulation data and measured results were given.(3) A variety of techniques used in antenna element were further studied, the effects of these in design were pointed out, these results can be references for relevant microstrip antennas.(4) Tolerance analysis and optimization analysis on antenna array had been did, the optimal arraying way were given.