The Research Of Coplanar Capacitive Coupled Low-profile Printed Antenna

With the rapid development of information technology, people's requirements of antenna performance are also increasing. Printed antennas have many advantages, such as small size, easy manufacturing and light weight. Microstrip antennas have won the favor of the antenna researchers, and toward multi-band, broadband, intelligent and small size direction. This thesis which is based on the method of bandwidth broadening and feeding technology, researched the performance of coplanar capacitive coupled printed antenna which has existed in the literature, and improved for the shortcomings of its pattern of asymmetric, and researched a symmetric coplanar capacitive coupling low-profile printed antenna. Design and production of a low-profile broadband printed antenna, and it carried out a detailed research and analysis. Based on the work above.Then change this structure to be used in dual-band wireless LAN antenna systems ,given the design process, produced a sample antenna, test results show the proposed coplanar symmetric capacitive coupling can be applied to low-profile printed antenna in a WLAN, it appears a new application for the type of antenna foundationThis thesis can be divided into five parts.First, the thesis discussed the background of the coplanar capacitive coupled low-profile printed antenna, introduced three simulation software.Secondly, the thesis described electrical parameters and the basic theory of printed antenna, and theory of broadband antenna was also described, describes several ways to broaden the printed antenna technology.Thirdly, the coplanar capacitive coupled low-profile printed antenna was researched. The size of the radiation plates, the coupling capacitor chip and other parameters were studied and compared and optimized in detail, and produced the corresponding antenna samples, test results show that the coplanar capacitive coupling can be broadband antenna.Fourthly, based on analysis of the coplanar capacitive coupled low-profile printed antenna structure, in the various structures analyzed, and used for dual-band wireless LAN system, the proposed coplanar symmetric low-profile dual-band capacitive coupled printed antenna structure, and simulation and optimization was carried out to produce a sample, the results show that the improved method is feasible.Finally, all the work of this research was summarized, and future research work was proposed.