基于菲涅尔透镜的天线方向图设计

发布时间：2018-06-10 16:46

本文选题：菲涅尔波带透镜 + 人工超材料　；参考：《电子科技大学》2017年硕士论文

【摘要】：菲涅尔波带透镜在方向图控制性能上有着优秀的表现,并且由于其制作简易和成本低廉的优势备受市场青睐,针对菲涅尔波带透镜的研究在国内外一直是一个极具发展前景的科研方向。菲涅尔波带透镜在传统介质材料透镜领域理论发展已经十分成熟,现在对菲涅尔波带透镜的研究主流方式是和人工超材料和半导体等新型材料领域的结合应用。由于人工超材料的特殊电磁传播性能,将人工超材料与菲涅尔波带透镜结合应用在方向图控制上的科研工作取得了很好的成绩,尤其是在高增益和波束扫描方向。该论文描述了结合菲涅尔波带透镜控制方向图的两种设计:可控超材料的菲涅尔波带透镜以及菲涅尔波带透镜与圆波导集成的波束天线。第一种设计基于常见的圆环,“十”字和“工”字周期结构单元,利用在单层FR4介质板异面合成的方法设计筛选出圆环与“十”字的异面单元,该单元比较另一种异面单元体现出更好的电磁诱导透明效应,而且该单元周期结构的电磁谐振点随着斜入射电磁波角度变化没有改变,超材料介质的电磁透射性能的变化可以忽略不计。结合微波谐振器电路等效原理,在周期结构中加载电容,可以改变单元的电磁透射性能,加载不同容值电容,可以控制周期单元在3.5GHz处的电磁谐振点由透明谐振点向不透明谐振点转换。结合利用偏置电压控制容值在6.5pF—1.5pF变化的变容二极管,设计研制了周期性结构的电控制超材料菲涅尔波带透镜。经过实验测试验证,该人工超材料在3.5GHz处的透射性能在0V直流偏压条件下为透射点,在7.1V直流偏压下转换为非透明点。利用该性能与菲涅尔波带透镜结合,改变波带位置的超材料介质的透射性,实现了对标准偶极子天线的0度、10度、20度和30度的波束扫描。第二种设计是将圆波导与菲涅尔波带透镜集成的高方向性波束天线设计。利用对圆波导馈源阻抗匹配转换的方法优化波束天线的辐射效率,在30GHz处波束宽度仅为4.4度,方向增益达到22.5dBi,在30.5GHz处波束宽度5.7度,增益达到21.5dBi。该波束天线后续展望是在圆波导端设计成合适的圆极化器,实现波束天线的圆极化。
[Abstract]:Fresnel zone lens has excellent performance in pattern control, and is favored by the market because of its simplicity and low cost. The study of Fresnel zone lens has been a promising research direction at home and abroad. The theory of Fresnel zone lens has been developed in the field of traditional dielectric lens. Now the main research mode of Fresnel zone lens is the combination of artificial supermaterial and semiconductor and other new material fields. Due to the special electromagnetic propagation performance of artificial supermaterial, the application of artificial supermaterial and Fresnel band lens in pattern control has achieved good results, especially in the direction of high gain and beam scanning. This paper describes two designs of Fresnel band lens control pattern: a controllable supermaterial Fresnel band lens and a beam antenna which integrates the Fresnel band lens with a circular waveguide. The first design is based on the common circular ring, "ten" word and "industrial" word periodic structure unit, using the method of hetero-surface synthesis in the single-layer FR4 dielectric plate to design and screen the off-plane elements of the ring and the "ten" character. The element shows better electromagnetically induced transparency than another hetero-planar element, and the electromagnetic resonance point of the periodic structure of the cell does not change with the angle of oblique incident electromagnetic wave. The change of electromagnetic transmission property of metamaterials is negligible. Combined with the equivalent principle of microwave resonator circuit, the electromagnetic transmission performance of the unit can be changed by loading the capacitance in the periodic structure, and the capacitance with different values can be loaded. The transition from transparent resonance point to opaque resonance point can be controlled at 3.5 GHz. Combined with a varactor whose bias voltage is controlled at 6.5pF-1.5pF, an electrically controlled supermaterial Fresnel band lens with periodic structure is designed and developed. The experimental results show that the transmission performance of the artificial supermaterial at 3.5 GHz is a transmission point at 0 V DC bias and converted to a non-transparent point at 7.1 V DC bias. By combining the performance with the Fresnel band lens, the transmission of the metamaterial medium with changing the position of the band is obtained, and the beam scanning of the standard dipole antenna is realized at 0 ~ 10 ~ 10 ~ 20 ~ 20 and 30 ~ (th). The second design is a high directional beam antenna which integrates circular waveguide with Fresnel band lens. The radiation efficiency of the beam antenna is optimized by matching the impedance of the circular waveguide feed. The beam width is only 4.4 degrees at 30GHz, the directional gain is 22.5dBi. the beam width is 5.7 degrees at 30.5GHz and the gain is 21.5dBi. The future prospect of the beam antenna is to design a suitable circular polarizer at the end of the circular waveguide to realize the circular polarization of the beam antenna.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN820

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