【作者】 陈龙；

【导师】 游彬；

【作者基本信息】 杭州电子科技大学 ， 电路与系统， 2015， 硕士

【摘要】 可重构通信系统作为未来通信系统的发展方向,越来越受到关注,作为可重构系统关键器件之一的可调射频滤波器也越来越受到重视。本文从理论分析到实际设计对可调滤波器展开了相关研究。首先,本文分析了经典滤波器设计中P(s)、F(s)和E(s)多项式系数提取到耦合矩阵综合的过程,然后结合可调滤波器自身的特点,计算了耦合矩阵在滤波器调谐过程中各个设计参数所需要满足的条件。提出通过经典的不可调滤波器加载调谐元件构成可调滤波器的设计流程,并从理论层面论述了其可行性及实施条件。基于这一设计理论,本文设计实现了多款可调滤波器,包括可调微带滤波器和在国内外文献中较少见的可调腔体滤波器。本文设计实现了一款微带结构的双通带双模滤波器。双通带中心频率分别为2.35GHz/3.35GHz。详细分析计算了所设计的SLR特性及其构成滤波器的设计流程。测试结果符合预期。在此基础上,通过加载变容二极管设计实现了一款微带结构的双通带三模可调射频滤波器。双通带中心频率分别在0.8~1.02GHz/2.02~2.48GHz可调。该滤波器采用了具有独创性的“T”型加载枝节,使可调滤波器所需的控制电压减少一半。该滤波器通过N+2阶耦合扩展,实现了6个传输零点,提高了可调滤波器的选择性。该滤波器与国内外同类滤波器相比具有调谐简便,选择性好等特点。腔体电可调滤波器是目前可调滤波器的难点,本文提出了一种可调SIW滤波器,推导了SIW谐振器加载调谐元件构成可调谐振器的原理。并基于此设计实现了一款可调SIW滤波器,测试结果证明该设计可以通过加载控制电压,控制滤波器的中心频率及外部Q值。这一滤波器的设计实现有助于进一步推动腔体电可调滤波器的研究和发展。更多还原

【Abstract】 As a key components of microwave reconfigurable communication systems,tunable RF filters have been a hot topic resent years. This thesis presents the theoretical analysis and design examples of tunable filters.First, this thesis analyzes the classic filter characteristic functions P(s), E(s)and H(s) to extract the coupling matrix. Then, a new design theory for tunable filters based on filter synthesis theory is proposed. It shows tunable filters can be realized base on untunable filters which loaded tuning elements.Based on this design theory, this thesis designed and fabricated several tunable filters, including a tunable microstrip filter and a tunable cavity filter which is quite rare in publicized papers.In this thesis, design and fabricate a dual-band dual-mode microstrip filter.Dual-band center frequency is 2.35 GHz / 3.35 GHz, respectively. Detailed analysis and calculation of the SLR design characteristics and design process constitute filter.The test results in line with expectations.On this basis, a novel varactor tunable dual-band bandpass filter using stub-loaded stepped-impedance resonators is proposed. Dual-band center frequencies are adjustable in 0.8 ~ 1.02 GHz and 2.02 ~ 2.48 GHz. the source-load coupling and T-shape stub-loaded lines are employed in this design. In the overall tuning range, the proposed filter is designed with 5-6 transmission zeros. This dual-band tunable filter has the advantages of high selectivity and less control voltages.The implementation of electrically tunable cavity filters is a difficulty in tunable filter design. This thesis presents a tunable cavity filter base on SIW technology.Both the theoretical analysis and the design process is presented. Fabricated results show that the control voltages loaded on the filter can control the center frequency and the External-Q. This design will help further promote of the electrically tunable cavity filters.更多还原