平面型慢波传输线及其小型化射频器件研究

Miniaturization of radio frequency devices is the trend of wireless communication applications in future. The devices of radio frequency have an importance influence on size of the mobile devices. Size constraints of radio frequency components have currently become the bottleneck of restricting miniaturization for devices of radio frequency in military and civilian wireless systems. This project takes planar slow-wave transmission lines as the main research object, and the theoretical and experimental studies are carried out on design for slow-wave transmission lines with quasi-lumped elements form and patch type and their applications on components of radio frequency. The concrete content includes: in view of similarity for the equivalent circuit model between the slow-wave structure and low-pass filter, the construction method of slow-wave structure which can meet the low-pass filtering performance is studied; Conditions of realizing broadband performance for n-section half-wave balun is derived to achieve compact half-wave balun based on slow-wave structure; In combination with both advantages of the slow-wave structures to improve the design of slow-wave transmission lines, design method for better performance of new type transmission line is put forward; Utilizing characteristics of slow-wave structures and double-sided parallel-strip lines, construction method of slow-wave structure with high impedance characteristics is studied, and design approach of balanced components with slow-wave structures is established. This project aims to establish design methodology of planar slow-wave structures and components of radio frequency to lay the theoretical and technical foundation for miniaturized high-performance components of radio frequency.

射频设备的小型化是未来无线通信应用的大趋势，而射频器件对移动设备的尺寸有着重要的影响。射频器件的尺寸目前成为制约军用和民用无线电系统中射频设备小型化的瓶颈。本项目以平面型慢波传输线为主要研究对象，对半集总元件形式和贴片式慢波结构传输线的设计及其射频器件应用进行理论和实验研究。具体内容包括：针对慢波结构与低通滤波器等效电路模型的相似性，研究满足低通滤波性能的慢波结构的构造方式；分析推导N阶半波巴伦实现宽带性能的条件，并基于慢波结构实现小型化半波巴伦；结合两种慢波结构的优势，改进慢波传输线的设计，提出更好性能的新型传输线的构造方法; 利用慢波结构与双面平行带状线电路的特点，研究高特性阻抗慢波结构的构造方式，并建立慢波结构的平衡器件设计方法。本项目旨在建立平面型慢波结构传输线及其射频器件的设计方法，为研制高性能的小型化射频器件奠定理论和技术基础。

射频器件小型化是未来无线通信应用的大趋势，对移动设备的尺寸有着重要的影响。本项目对平面型慢波传输线在射频器件中的应用进行了研究，主要针对半集总元件形式慢波传输线和贴片式慢波传输线这两个方面展开了理论分析和应用研究，取得了一系列有特色的创新性成果。在半集总元件形式慢波传输线方面，建立起慢波传输线电路模型与经典低通滤波电路之间的关系，构建了基于慢波结构的具有一个传输零点的低通滤波器和具有两个传输零点的低通滤波器，构造了基于慢波结构的二阶半波巴伦，并利用双面平行带状线和慢波结构造出了平衡型等分功分器和具有高抗阻传输线的不等分功分器。在贴片式慢波传输线方面，建立起三角形贴片式慢波结构电路模型与阶梯阻抗传输线等效电路之间的关系，并应用三角形贴片式慢波结构构建等分功分器和耦合器。在其他方面，研究了共面波导电路形式下的慢波传输线，构建了基于共面波导的周期性慢波传输线单元，以及对于基于交叉结构的混合左右手传输线，利用多层板技术和单层微带电路分别进行了构造和实现。