可重构天线的研究及其在时间反演系统中的应用

发布时间：2018-01-10 10:38

本文关键词：可重构天线的研究及其在时间反演系统中的应用　出处：《电子科技大学》2016年博士论文　论文类型：学位论文

【摘要】：现代无线信息系统面临着两方面的挑战,一是系统本身需要实现多极化、多波段、低功耗、小型化和综合集成化;二是系统外部的工作环境越来越复杂,通信节点分布广泛且具有随机性。鉴于可重构天线可通过切换工作状态,利用单个天线口径实现多个天线的功能;而时间反演技术可以克服多径效应,实现时间—空间的同步聚焦,故可重构天线技术和时间反演技术为应对这两重挑战提供了新的思路和方法。本论文以可重构天线的研究及其在时间反演系统中的应用为课题,主要研究内容概述如下:第一部分主要对可重构的圆柱形介质谐振器天线进行了研究,分别实现了方向图和极化的可重构。首先,介绍了圆柱形介质谐振器天线的基本理论,并以一个双端口多频带圆柱形介质谐振器天线的设计为例进行说明。然后,利用圆环缝隙耦合馈电结构,设计了一个方向图可重构的介质谐振器天线。天线利用高次模辐射获得了准端射的方向图,通过切换加载在馈电缝隙上的8个开关,可实现方向图在水平面内的旋转。最后,进一步挖掘了圆柱形介质谐振器和馈电圆环的对称性,提出了一种极化可重构的圆柱形介质谐振器天线。天线利用圆环缝隙激励起两个等幅正交的模式,并引入90°相位差。天线仅使用两个加载在馈电缝隙上的开关,即可实现左旋和右旋圆极化的可重构。上述两种可重构天线具有馈电简单,开关和直流偏置电路对天线影响小等优点。第二部分主要研究了极化可重构的微带贴片天线。首先,为对微带贴片天线进行全波分析,介绍了一种重要的数值计算方法——时域有限差分法,并对普通贴片天线的的辐射过程进行了仿真。然后,设计了一款极化可重构的圆形贴片天线,天线采用单端口馈电,并利用4个PIN开关,实现了线极化、左旋圆极化和右旋圆极化的可重构。切换极化方式后,天线仍具有较宽的带宽、高增益和低交叉极化特性。最后,设计了一个双端口的极化可重构方形贴片天线,每个端口均可实现线极化、左旋圆极化或右旋圆极化。当其工作于线极化模式时,该天线也可视为一个频率可调的双极化天线。上述两种极化可重构的微带天线均由两层介质基板构成,均采用空气介质和缝隙耦合馈电,可抑制表面波,简化PIN开关的直流偏置电路。第三部分主要开展了可重构天线在时间反演应用系统中的研究。首先,推导了利用模数混合技术实现时间反演的过程,使用时域有限差分法进行了仿真,结果验证了时间反演技术的时间—空间同步聚焦特性,进而利用时间反演技术对多目标和运动目标进行了场重构。然后,针对无线传感器网络节点供能的问题,研究了基于时间反演技术的微波输能系统。传统的微波输能技术在多个发射端同时发射时,某些特殊位置的电磁波会反相叠加,导致输能效率低下。基于时间反演的微波输能系统将能有效克服这个问题。本文将所设计的方向图可重构介质谐振器天线用于发射端,提高了输能效率;并研究了接收端的关键器件——整流电路,设计了一个双频整流电路。最后,结合所设计的双端口极化可重构贴片天线,研究了不同极化形式的时间反演电磁波在金属细导线阵列中的超分辨聚焦特性。结果证明,可通过切换极化方式来获得关于目标更清晰的结果。
[Abstract]:The modern wireless information system faces two challenges, one is the system itself needs to realize multi polarization, multi band, low power consumption, miniaturization and integration of the system; two is outside the work environment more and more complex, the communication nodes are widely distributed and is random. In view of the reconfigurable antenna can be achieved by switching the working state. The functions of multi antenna using a single antenna aperture; and time reversal technique can overcome multipath effect, realize synchronous focusing in space and time, so the reconfigurable antenna technology and time reversal technique for new ideas and methods for dealing with these two challenges provided. In this paper, research on reconfigurable antenna and its application in inversion system in the paper, the main contents are summarized as follows: the first part mainly studied the cylindrical dielectric resonator antenna with reconfigurable, respectively realized the direction and polarization of the Reconfigurable. Firstly, introduces the basic theory of cylindrical dielectric resonator antenna, and to design a dual port multi band cylindrical dielectric resonator antenna as an example. Then, using the ring slot coupling feeding structure, the dielectric resonator antenna with reconfigurable design. One direction antenna using high-order mode radiation quasi end radiation pattern, by switching the load in the feed slot on the 8 switch, can realize the direction map of the rotation in the horizontal plane. Finally, to further tap the symmetry of the cylindrical dielectric resonator and the feeder ring, a cylindrical dielectric resonator antenna with a polarization reconfigurable antenna. Using the ring slot excited two a constant amplitude orthogonal mode, and introduces the 90 degree phase difference. The antenna switch using only two loading in the slot, you can achieve left-handed and right-handed circular polarization reconfigurable above. Two kinds of reconfigurable antenna has the advantages of simple feed, switch and a DC bias circuit of antenna effect is small. The second part mainly studies the Polarization Reconfigurable Microstrip Patch antenna. Firstly, for the full wave analysis of microstrip patch antenna, introduces an important numerical method of finite difference time domain method, and the radiation process of the common patch antenna is simulated. Then, the circular patch antenna with a polarization reconfigurable antenna design, using single feed, using 4 PIN switch, the linear polarization, left-hand circular polarization and right-hand circular polarization reconfigurable antenna polarization switching. After, still has a wide bandwidth, high gain and low cross polarization characteristics. Finally, a dual port Polarization Reconfigurable square patch antenna design, each port can realize linear polarization, left-hand circular polarization or right-hand circular polarization. When the work In the linear polarization mode, dual polarized antenna, the antenna can also be regarded as a frequency tunable microstrip antenna. The two Polarization Reconfigurable are composed of two layers of dielectric substrate, using air medium and coupling feed, can suppress the surface wave, DC bias circuit simplified PIN switch. The third part mainly carried out research on time reversal in the application system of reconfigurable antenna. Firstly, the realization process of time inversion using hybrid technology is deduced, using the finite difference time domain method. The simulation results verify the synchronous focusing characteristics of time reversal technique of time - space, and then use the time reversal technique of multiple targets and moving targets. Field reconstruction. Then, according to the wireless sensor network node energy supply problems, study the microwave time inversion of the energy system. Based on the traditional microwave transmission technology in multiple transmitter At the same time when transmitting electromagnetic wave will reverse the specific location of the stack, resulting in low efficiency. The output microwave time inversion of the energy system will be able to overcome this problem. Based on the design of pattern reconfigurable dielectric resonator antenna for transmitter, improves the transmission efficiency; and studies the key - rectifier circuit device at the receiver, a dual frequency rectifier circuit design. Finally, combined with the design of Polarization Reconfigurable Microstrip antenna, the time inversion of electromagnetic wave with different polarization in the form of a thin metal wire array in super-resolution focusing properties. The results showed that, by switching polarization way to get clearer about the target results.

【学位授予单位】：电子科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN820

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