交叉耦合射频电调滤波器研究

Radio Frequency (RF) electrical tunable filter with the reconfigurable frequency response capability is the essential components for future frequency agile RF communications. However, traditional tunable coupled resonating structures are lack of independent and controllable electric coupling path and magnetic coupling path, which limits the development and application of cross-coupled RF tunable electrical filters. This project aims at the research of the electrical tunable resonating structures with independent and controllable electric and magnetic coupling path, the feeding networks, and the synthesis and design of novel cross-coupled tunable topologies. The research includes the following critical problems: (1) electrical tunable resonators with independent and controllable electric coupling path and magnetic coupling path; The control mechanisms of the independent electric and magnetic coupling path. (2) Interaction mechanisms and control methods of the feeding network and the tunable resonator with independent electric and magnetic coupling path. (3) Synthesis and design of advanced electrical tunable cross-coupled RF filter topologies, i.e., CT (Cascaded Trisection) types, CQ (Cascaded Quadruplet) types.

射频电调滤波器具有可重构频响特性，是实现射频通信“宽频普适化”的核心器件。传统平面集成电调耦合调谐结构缺乏兼具电、磁两种类型且独立可控的耦合通道，限制了交叉耦合射频电调滤波器这类高级拓扑的发展与应用。本课题通过构建电、磁双耦合调谐结构及其馈电网络，研究交叉耦合新型电调滤波器拓扑结构及其综合设计方法。研究内容包括：（1）构建电、磁双耦合可调谐振器，研究其电、磁耦合系数的调控机制；（2）研究电调滤波器馈电网络与双耦合可调谐振器的相互作用机制与调控方法；（3）研究交叉耦合可调滤波器拓扑结构及其综合方法，设计CT (Cascaded Trisection)、CQ (Cascaded Quadruplet)等类型交叉耦合射频电调滤波器。

射频电调滤波器具有可重构频率响应特性，是实现射频通信“宽频普适化”、电磁频谱动态抗干扰的核心器件。传统电调滤波器缺乏耦合系数与谐振频率协同调控的有效手段，导致调谐过程中滤波器通带宽度稳定性差，影响链路通信带宽的稳定性。同时，传统平面集成小型化调谐结构品质因数低，导致其带外抑制能力不够，从而限制了无线链路设备的抗干扰能力。针对以上难题，本项目提出了多种电/磁独立双耦合谐振结构，利用单一谐振器实现了多个独立的电、磁耦合通道，且可与谐振频率协同调控；基于此构建了常带宽高阶交叉耦合电调滤波器，采用交叉耦合拓扑技术突破了由平面低品质因数谐振器导致的电调滤波器带外抑制能力差的局限，提升了滤波器的带外干扰抑制能力。基于本项目理论，本项目已构建了三阶、四阶、五阶、六阶CT和CQ等一系列基本交叉耦合恒定带宽可调谐滤波器拓扑结构，以及带宽、中心频率、传输零点可重构的交叉耦合电调滤波器拓扑结构。项目有关研究成果已在微波射频国际主要期刊发表SCI检索期刊论文11篇，发表中文核心及EI期刊论文2篇，参加EuCAP、IEEE MTT-S IWS、微波年会等国内外学术会议并发表论文9篇，已申请中国发明专利3项，获授权1项。