| With the development of the wireless communication, wide-band antenna has been used widely. Especially, the omni-directional wide-band antenna which covers GSM, CDMA, WCDMA, TD-SCDMA for mobile communication is required. So, wide-band omni-directional antenna should be had higher performance in the indoor based communications. The required antenna should have wider impedance bandwidth which included 800MHz-960MHz and 1710MHz-2500MHz, smaller size, higher gain. So, the antenna can meet indoor base station and subarea communications. According to the requirement, the theory of wide-band tapered slot antenna, GTD, Rotating field theory, electromagnetic simulation technologies and experiment method are employed to design a wide-band omni-directional tapered slot antenna. The detailed discussion and analysis of the proposed tapered slot antenna is presented in the thesis. The proposed antenna was also fabricated and measured in the thesis. In additional, the proposed tapered slot antenna was inproved. A method which can give high gain was prostented in the last of the thesis to inprove the gain of the omni-directional tapered slot antenna.The wideband omni-direvtional antenna used in the mobile and the key parameters in the mobile communication was introduced first. And the shape of the tapered slot antenna and other wide-band omni-directional antenna used in the mobile communication had also been given. Then the concept and expression of the key parameters such as impedance width, radiation pattern, Voltage Standing Wave Ratio (VSWR), return loss, gain are introduced and discussed.The major content of this thesis can be divided into two parts. The first part is the design of the wide-band omni-directional tapered slot antenna. The tapered slot antennas consist of exponential line and straight line. The designed antenna is analyzed by using High Frequency Structure Simulator (HFSS) which based on Finite Element Method (FEM). Then the proposed antenna was optimized, analyzed, manufactured and measured. The second part is the improvement of the proposed wideband omni-directional tapered slot antenna. In this part, two improved parasitic antenna are presented numerically and experimentally. The parasitic tapered slot antennas were also analyzed in the thesis. The impedance width, radiation pattern, gain of the parasitic tapered slot antennas were measured and compared to the monopole antenna and the sleeve monopole antenna which is used in the mobile communication widely. In additional, a method of design higher gain omni-directional tapered slot antenna was also given. The method was also verified by experiment.At last, I summarize the research of this thesis. And the advantage and disadvantage of the proposed antenna and some valuable orientations and contents are given in the last of the thesis. The proposed advance can give some guide for follow-up study of wideband omni-directional tapered slot antenna. |
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