The Study And Design Of Dual-band Printed Antennas

In recent years, with the rapid progress of wireless communication technology, the applications in mobile communications and WLAN systems are widespread. Meanwhile, various dual-frequency systems have emerged and the research of dual-frequency antenna have received more and more attention. Printed antenna has become the first choice for dual-frequency antenna design due to its low cost and simple structure. And its media board can be used to achieve wideband operation and dual-band operation. In this paper, Based on the study of the dual-frequency antenna theory and method, two types of printed dual-frequency antennas have been designed and achieved: dipole antenna and monopole antenna.This paper is divided into six parts. The first part of this paper describes the research background and the current development status of dual- frequency antenna. The second part describes the theoretical basis of antennas which include antennas'electrical parameters, dipole antennas, monopole antennas, matching technology. And then the technology of dual-frequency antenna is described. Furthermore, several methods to achieve the dual-frequency technology are analyzed. Based on the above theoretical basis of the previous chapters, two types of dual-frequency antennas are proposed and developed for the applications in WLAN systems. Both two types are printed dual-frequency dipole antennas and the rest one is a printed dual-frequency monopole antenna. These two types of antennas are able to cover the standard of IEEE802.11a/b/g(2.4GHz(2412-2484 MHz),5.2GHz(5150-5350 MHz)and 5.8GHz(5725-5825MHz)) after several simulations. And then the printed monopole antenna for physical production, and network analyzer is measured, the measured results and the simulation results are basically consistent. It is shown that the proposed antennas are suitable for WLAN system applications.Finally, this paper has summarized all the work and prospected the related studies in future.