Multi-Band Terminal Antenna Technology Research

With the rapid development of the mobile communication, spectrum resources become increasingly scarce. The wireless communication system has been developing towards wide band, miniaturization, integration and multi band, which has given rise to the urgent demand for multi band antennas. In recent years, as a new type of planar transmission line, the substrate integrated coaxial line becomes a hot topic of research.This dissertation mainly focuses on the study of the substrate integrated coaxial line and multi band antenna technology, including following parts:Firstly, this dissertation simply discusses the background of the substrate integrated coaxial line and multi band antenna technology. Some basic theory and parameters of the antenna are reviewed. The basic theory of the monopole antenna is emphatically introduced.Secondly, a new calculating method for the equivalent width for the double layer dielectric substrate integrated coaxial line is proposed:Equivalating he substrate integrated coaxial line to rectangular coaxial line, the relationship between the equivalent width of the equivalent rectangular coaxial line and the substrate-integrated coaxial line is obtained. This method simplifies the design for the microwave and millimeter wave device based on substrate integrated coaxial line.Lastly, a new design planer for a dual band monopole antenna with a ring and two T structure is proposed. The dual band antenna is fed by micro-strip line directly and it works at 2.5GHz and 3.5GHz. In the operating band, it shows wide impedance bandwith and omnidirectional feature.