高温超导滤波器中异步调谐复杂交叉耦合技术研究

Traditional cross-coupled resonator technology, which is often used for designing high-temperature superconducting (HTS) filter, can only tune resonators synchronously with frequency-independent couple coefficient and unclear cross-coupled physical meaning. In order to solve these problems, a novel asynchronously tuned complex cross-coupled technology is proposed in this experiment. Furthermore, new mixed coupled resonator equivalent circuit model is designed and new frequency-dependent couple coefficient is defined, by which the new filter synthesis theory based on the asynchronously tuned complex cross-coupled theory is built. After investigating the asynchronously tuned complex cross-coupled resonator's effort on the couple unit and the whole filter, the special cross-coupled coefficients are derived for the low group delay and the good sideband performance. Finally, the new filter layout of HTS filters with better machining error tolerance and new coupled method between the source/load and the resonators with better coupled coefficient are proposed to enhance the asynchronously tuned complex cross-coupled HTS filter's design flexibility. The proposed asynchronously tuned complex cross-coupled technology not only expands the cross-coupled filter's application range but also increases the HTS filter's design parameter and reduces the optimization time. So it is significant in theory and engineering when it is used to design the multi-band and broadband HTS filter.

为了解决高温超导滤波器所采用的传统交叉耦合理论只能同步调谐、耦合系数固定不变和混合耦合物理意义不明的问题，本项目提出了异步调谐复杂交叉耦合理论。通过理论推导，本项目建立了新的混合耦合电路模型，定义了新的频变耦合系数，并在此基础上提出了异步调谐复杂交叉耦合滤波器综合理论。然后，本项目通过讨论异步调谐中复杂交叉耦合对谐振单元和滤波器的性能表现，求解了降低滤波器群时延和增强滤波器边带性能的交叉耦合系数所需要满足的条件。为了增强基于异步调谐复杂交叉耦合理论的高温超导滤波器设计的灵活性，本项目提出了抗容差的高温超导滤波器的二维平面布局和能够增强源/负载和谐振器耦合强度的耦合方法。本项目不仅在理论上拓宽了交叉耦合理论的内涵，而且在工程上增加了滤波器的设计变量，缩减了优化时间，在指导多通带和宽带高温超导滤波器的设计上具有重要的理论意义和工程价值。

相比常规滤波器，超导滤波器具有带内插入损耗低、带内群时延波动小、带外抑制能力强和滚降系数高等诸多优点，是微弱信号探测、空间卫星通信和雷达等高灵敏度探测领域必不可少的关键器件。为了解决传统超导滤波器所用同步交叉耦合设计技术中可调参数少等问题，本项目研究了高温超导滤波器的异步交叉耦合机理及实现方式，主要研究内容包括三个方面。首先研究了异步调谐复杂交叉耦合机理和综合理论。建立了精准的异步调谐复杂交叉耦合的等效电路模型，该模型能更加准确的表明不同谐振器的混合耦合，表明耦合系数随频率变化的关系。构建了异步调谐复杂交叉耦合滤波器综合方法，为工程师设计构建所需的异步调谐复杂交叉耦合滤波器提供耦合系数初始值和谐振器的布局结构。其次研究了异步调谐复杂交叉耦合对滤波器性能表现的影响。研究了异步调谐复杂交叉耦合滤波器边带抑制的影响因素和群时延的影响因素，研究了级联三单元和级联四单元谐振器的交叉耦合性能表现，为最终的异步调谐复杂交叉耦合滤波器的成功研制奠定好理论基础。再次研究了异步调谐复杂交叉耦合高温超导滤波器的实现方式。研究了高温超导薄膜的非理性特性对滤波器性能的影响，研究了高温超导滤波器大耦合量耦合实现方式，研究了无交叉耦合线的异步调谐交叉耦合高温超导滤波器。该项目的研究成果包括SCI论文6篇，EI国际会议论文5篇，译著一本，授权发明专利一项，部分成果已经用于某国防项目，并且参与该项目的6名研究生顺利毕业。申请时预计研究内容、研究目标和研究成果业已全部实现。