微带天线加载BST铁电薄膜可重构技术研究

发布时间：2018-11-22 20:43

【摘要】：随着具有大容量、超宽带等特征的综合信息系统的迅猛发展,同一载体上需要的信息子系统数量不断增加,这使得接收和发送信息的天线数量也相应增加。同一载体上天线数量的增加将产生诸多问题,如负重增加、天线间电磁干扰等,采用具有多天线功能的单一天线可以很好的解决上述问题,此单一天线定义为可重构天线。在可重构天线中,以微带天线为载体的研究最为广泛,原因在于微带天线所固有的重量轻、低成本、低剖面、易于与物体共形等特点。传统的微带天线往往通过控制PIN二极管或MEMS开关的通断来实现频率、方向图或极化方式可重构。本文研究了一种新颖的可重构方法,即在微带天线上加载BST(钛酸锶钡)铁电薄膜实现频率和方向图可重构,其具有参数调节方便、频率连续可调、电场分布均匀等特点。本文主要对以下两个方面进行了研究:1.微带天线加载BST铁电薄膜频率可重构技术研究研究了BST铁电薄膜不同加载位置(辐射贴片底部和四周)和参数(宽度和厚度)对谐振频率、输入阻抗和方向图的影响情况;在普通微带贴片天线中的辐射贴片底部和四周加载BST铁电薄膜实现了频率可重构;在微带偶极子天线中的对称阵子臂底部和四周加载BST铁电薄膜实现了频率可重构。2.微带八木天线加载BST铁电薄膜方向图可重构技术研究研究了两单元微带八木天线加载BST铁电薄膜的情况,改变加载于无源贴片底部和四周的BST铁电薄膜介电常数值,实现了无源贴片引向功能和反射功能的相互转换;在三单元微带八木天线中的两无源贴片底部和四周均加载BST铁电薄膜,改变两者介电常数值的相对大小,实现了方向图可重构;对方向图可重构中出现的工作频率处谐振深度不够好、方向图副瓣电平较高的问题进行了分析,通过在有源贴片上开槽对问题进行了较好的解决,构成了改进的可重构三单元微带八木天线。
[Abstract]:With the rapid development of integrated information systems with large capacity and ultra-wideband (UWB) characteristics, the number of information subsystems needed on the same carrier is increasing, which makes the number of antennas receiving and transmitting information increase accordingly. The increase of the number of antennas on the same carrier will cause many problems, such as the increase of the load, the electromagnetic interference between antennas, and so on. Using a single antenna with multi-antenna function can solve the above problems well. This single antenna is defined as a reconfigurable antenna. Among the reconfigurable antennas, microstrip antennas are the most widely studied because of their inherent characteristics of light weight, low cost, low profile and easy conformal with objects. Traditional microstrip antennas can be reconfigurable by controlling the on-off of PIN diodes or MEMS switches. In this paper, a novel reconfigurable method is studied, that is, loading BST (strontium barium titanate) ferroelectric thin film on the microstrip antenna to reconfigure the frequency and pattern, which has the advantages of convenient parameter adjustment, continuous frequency adjustment, uniform electric field distribution, and so on. This paper mainly studies the following two aspects: 1. The influence of different loading positions (bottom and circumference of radiation patch) and parameters (width and thickness) on resonant frequency, input impedance and pattern of BST ferroelectric thin film loaded by microstrip antenna were studied. The frequency reconfiguration is realized by loading BST ferroelectric thin film at the bottom and around the radiation patch of the ordinary microstrip patch antenna, and the frequency reconfiguration is realized by loading the BST ferroelectric film at the bottom and around the symmetrical quad arm of the microstrip dipole antenna. 2. Reconfigurable technique of BST Ferroelectric Film pattern for microstrip Yagi Antenna the loading of BST ferroelectric thin films by two element microstrip Yagi Antenna is studied. The dielectric constant values of BST ferroelectric thin films loaded at the bottom and around the passive patch are changed. The conversion between the leading function and the reflection function of the passive patch is realized. The BST ferroelectric thin films are loaded on the bottom and all sides of the two passive patches in the three element microstrip Yagi antenna. The relative size of the dielectric constant values is changed and the pattern can be reconfigurable. The resonance depth at the working frequency is not good enough and the sidelobe level is high in the direction diagram reconfiguration. The problem is solved by slotting on the active patch. An improved reconfigurable three-element microstrip Yagi antenna is constructed.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN822

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