可调射频滤波器的设计与实现

发布时间：2018-11-28 07:23

【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。
[Abstract]:As the development direction of the future communication system, reconfigurable communication system has attracted more and more attention. As one of the key components of the reconfigurable system, the tunable RF filter has been paid more and more attention. In this paper, the tunable filter is studied from theoretical analysis to practical design. Firstly, this paper analyzes the process of extracting the coefficients of P (s), F (s) and E (s) polynomials to the coupling matrix synthesis in the classical filter design, and then combines the characteristics of the tunable filter itself. The conditions required for the design parameters of the coupling matrix in the filter tuning process are calculated. The design flow of tunable filter based on the classical tunable filter loaded with tunable elements is presented. The feasibility and implementation conditions of the tunable filter are discussed theoretically. Based on this design theory, several tunable filters are designed and implemented, including tunable microstrip filters and tunable cavity filters, which are rare in domestic and foreign literatures. In this paper, a dual pass band double mode filter with microstrip structure is designed and implemented. The central frequency of double pass band is 2.35 GHz / 3.35 GHz. The SLR characteristics and the design flow of the filter are analyzed and calculated in detail. The test results were in line with expectations. On this basis, a dual-pass three-mode tunable RF filter with microstrip structure is designed by loading varactor diode. The center frequency of double pass band is adjustable in 0.8~1.02GHz/2.02~2.48GHz. In this filter, the original "T" loading section is used to reduce the control voltage required by the adjustable filter in half. The filter achieves six transmission zeros by N _ 2 coupling expansion and improves the selectivity of the tunable filter. Compared with similar filters at home and abroad, this filter has the advantages of simple tuning and good selectivity. Cavity electrically tunable filter is a difficult problem for tunable filters at present. A tunable SIW filter is proposed in this paper. The principle of tunable resonator with tunable elements loaded by SIW resonator is deduced. An adjustable SIW filter is implemented based on this design. The test results show that the design can control the center frequency and the external Q value of the filter by loading the control voltage. The design and implementation of this filter is helpful to further promote the research and development of cavity electrically tunable filter.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713

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