| Millimeter wave communication technology is an important development direction of 5G commercial deployment and 6G pre-research planning.As one of the key components of the front end of the millimeter wave system,the structure and performance of millimeter wave antenna determine whether the millimeter wave communication system can meet the commercial layout and strategic planning.At present,the main challenge of millimeter wave antenna is to propose new technologies to achieve broadband,high gain and beam scanning,while meet the needs of miniaturization,light weight and integrated low-cost antenna structure design.Therefore,this thesis proposes dielectric loading technology to study high performance and low-cost antenna and array design.Firstly,a circularly polarized dielectric loaded tapered slot antenna is presented for millimeter wave indoor communication application.The basic and high modes are excited in the dielectric waveguide.The working mechanism of wideband circular polarization radiation performance is clarified by orthogonal modes combination.A Z-shaped dielectric transition is proposed to realize the low-loss wideband impedance matching from the metal waveguide to dielectric waveguide within 2432GHz.The test deviation caused by antenna machining error based on 3D printing technology is discussed.By comparing the performance of dielectric antenna and metal antenna based on complementary structure,it is proved that the dielectric loading technology can make the antenna achieve miniaturization and light weight,which lays a theoretical foundation for the application of this technology in indoor communication.Secondly,a half mode Vivaldi beam scanning antenna array is proposed for millimeter wave outdoor communication application.Based on the mirror theory,the overall miniaturization design of the antenna is completed.With the single-column metal vias,the isolation between antenna elements is improved,which is increased from 8dB to 15dB at 28GHz.Thanks to the half mode structure,the array spacing is 0.47λ(@28GHz).The array scanning angle can cover from-51°to 47°,and gain fluctuations in the scan range are below 0.96dB.The antenna can achieve a light weight compact design through dielectric loading technology.With wide angle scanning and low gain fluctuation,the proposed antenna provides reliable solution for millimeter wave outdoor communication application.Finally,a planar dielectric loaded MIMO antenna is proposed for millimeter wave mobile terminals.By optimizing the shape of the radiation gap,the proposed MIMO antenna achieves the impedance bandwidth from 57GHz to 71 GHz.The dielectric cover changes the phase distribution of the electromagnetic wave and increases the peak gain of the antenna element to 12.33dBi without affecting the impedance matching.The energy decoupling between MIMO antenna elements is realized by the polarization diversity method and the insertion of the metal vias.With high gain,wideband,light weight and easy integration characteristics,the proposed antenna has a great advantage in the millimeter wave mobile phone terminals.Based on the dielectric loading technology,this thesis investigated the low cost,miniaturization and light weight millimeter wave antenna designs for indoor communication,indoor communication and mobile phone terminal.Fundamentals and engineering demonstration are presented for the antenna design in the field of millimeter wave communication. |
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