Researches On Dual-polarization Pattern Reconfigurable Antennaand Its Array

In recent years, with the development of global electronic and communication technology, wireless communication has become an essential part of people’s lives. The antenna is used as one of the core components of wireless communication systems, and act as the roles of reception and transmission of electromagnetic waves. Antenna performance will affect the communication quality of the wireless communication system. Meanwhile, the wireless communication system are required the large capacity,wide bandwidth, miniaturization, and anti-jamming capacity, so antenna meet the new demands. As we know, dual-polarized antenna can eliminate or reduce the impact of multipath effects by polarization diversity, increase the communication capacity and improve the spectrum utilization. Pattern-reconfigurable antenna can change the radiation beam, enable these systems to avoid noisy environments, maneuver away from electronic jamming, improve security, and save energy by better directing signals toward intended users. Compared with the conventional phased array, pattern reconfigurable technology has a simple structure, low cost, small size and other characteristics. In the thesis, a pattern reconfigurable antenna is combined with the dual linear-polarization antenna effectively, and dual-polarization pattern reconfigurable antenna elements and arrays are studied. In this paper, the content will be introduced briefly.The first chapter introduces the research background and topic basis of the subject.the backdrop and research status of pattern reconfigurable antennas, array and dual-polarized antennas at home and abroad are given in detail.Chapter II introduces the theories of microstrip antenna, Yagi-Uda antenna, array antenna and dual-polarized antenna. Besides, basic theory about the structure,classification, principle, and the method of microstrip antenna, including equally spaced linear arrays are presented in detail.Chapter III introduces the design of two dual linear-polarization pattern reconfigurable microstrip patch antenna, which are based on the principle of Yagi antenna. Fed by the probe coupling, antenna one can achieves three operation modes by controlling the PIN switches installed on the parasitic elements. Antenna one can obtaina wide common bandwidth of 460 MHz. Unlike antenna one, antenna two is couple feed by microstrip line. Antenna two can achieve four operation modes by controlling the PIN switches. And isolation between two ports is above 30 dB.In Chapter IV, A two-element dual linear-polarization pattern reconfigurable antenna array is presented. By controlling the PIN switches on the ground, the array can obtain four operation modes and achieve good impedance matching. At the last, the measured results and simulation results are given and analyzed.The last chapter gives the summary of the whole thesis and the outlook of future work.