| As the development of Wireless communication technology, the bandwidthresources becomes increasingly Shortage. The existed frequency has showed a trend ofsaturation for both its containment and a higher communication rate, so the terahertz(THz) communication technology emerged as the times require. As an indispensablepart of terahertz (THz) communication system, terahertz communication antennasbecame a hot topic of scientific research in these years. From the traditional mechanicalantennas and planar antennas to new-style antennas made of nanophase materials, THzcommunication antennas performed more and more satisfactorily.However, owning to the high frequency, the relative wavelength of terahertz isvery small. THz Communication antennas suffered from high electromagnetic loss,few useable materials and fragile structure. So, we must be very careful when choosethe material and processing technic of the THz antennas. In particular, planar antennason thick substrates suffer from power loss into substrate modes. One way to avoid thisproblem is to change the structure of the planar antennas.This paper focuses on the analysis and design of broadband antennas suitable to a0.3THz communication systemThe first chapter firstly introduced the background and status quo at home andabroad of terahertz systems and terahertz antennas technology, and then explained theimportance of terahertz communication antennas, and concluded the contents of thispaper at the last of this chapter.The second chapter described several important electrical parameters of antennasto evaluate the performance of the antennas mentioned. This chapter also presentedcomprehensive review of antennas suitable for terahertz applications, and simulatedsome typical THz antennas in order to make comparison and summary.The main task of the third Chapter was to design broadband antennas suitable forcommunication systems which worked on0.3THz. Considering the workingenvironment of the0.3THz communication systems, parameters of the antenna wasfixed at the beginning. Bow-tie antennas were chosen for this design. A bow-tie antenna could be fed by either CPW or CPS. A bow-tie antenna fed by CPS wascomposed of two piece of triangle metal slice. On the contrary, a CPW fed bow-tieantenna was made of a piece of metal slice which was cut by two triangles at the center.The bow-tie antenna was designed so that the input impedance was50Ω, thebandwidth was no less than20%, and the resonant frequency was about300GHz. Atthe same time, the CPW and CPS must be designed to achieve a characteristicimpedance of50Ω. Modified the model designed to ensure these parameters. In orderto obtain high gain and satisfactory directionality, an extended hemispherical lens waschosen based on detailed simulation to couple the bow-tie antenna. Some factors thataffected the radiation pattern of the extended hemispherical lens were investigated,such as radius R of the lens, extension length L of the extended hemisphere, the placeof the dipole and the effect of a match cap. Owning to the preparatory work, lenscoupled bow-tie antennas designed in this chapter had achieved the designspecifications.The fourth chapter studied the processing technic and assembly technology ofTHz antennas. Firstly, there is a comparison between traditional and emergingprocessing technic used to machine THz antennas. Then, a few suggestions aboutassembly technology of THz antennas were proposed.Chapter Ⅵ summarized the contents of the full paper, and indicated theadvantages and disadvantages of the THz lens coupled Bow-tie antenna designed in thethird chapter. Finally, looked into the future of the THz technology. |
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