基于多模谐振器的电可调滤波器设计和研究

发布时间：2018-01-15 06:15

本文关键词：基于多模谐振器的电可调滤波器设计和研究　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：电可调滤波器作为滤波器的一种重要类型,在无线通信及电子侦察系统方面扮演着越来越重要的角色。如何实现微带滤波器工作频段和带宽的可调化成为了一项极具研究价值的工作。作为实现电可调滤波器的方法之一,基于变容二极管的电可调滤波器以快速的电调响应,简易的偏置电路结构,连续的频率调谐和低廉的制作成本,在电可调滤波器的设计中广受欢迎。本文研究的重点也正是基于变容二极管的电可调滤波器。本文首先调研电可调滤波器最新研究进展,结合微带滤波器的设计理论和分析方法,在基于多模谐振器的结构上,介绍了电可调滤波器的设计理论。在该理论的基础上,本文一共设计了五款微带滤波器,包括一款双频带通滤波器,一款中心工作频率电可调滤波器,一款中心工作频率和带宽全可调滤波器,一款电可调低通滤波器和一款谐波抑制范围可调的电可调滤波器。本文设计的中心工作频率电可调的滤波器是在双频带通滤波器的基础上,基于短路枝节线加载谐振器和一对相互耦合的四分之一波长谐振器来实现的。相比于现有电调滤波器,该滤波器将插入损耗基本控制在5dB以内的同时,相对带宽维持在10%以上,改善了现有电调双频滤波器的窄带特性。本文中的全可调滤波器基于阶梯阻抗谐振器结构,通过极点的调节完成对该滤波器的全可调,与现有全可调滤波器相比,该滤波器工作频率的平移范围达到了 380MHz,工程应用价值较高。本文通过将截止频率电可调的低通滤波器和中心工作频率电可调的带通滤波器相级联的方法,设计了可以对电可调滤波器中动态偏移的高次谐波分量进行抑制的滤波器。与现有电调滤波器相比,该滤波器的谐波抑制范围能跟随该滤波器的中心工作频率进行移动,高次谐波分量抑制明显,有效提高滤波器工作中的稳定性。
[Abstract]:Electric tunable filter is an important type of filter. It plays a more and more important role in wireless communication and electronic reconnaissance system. How to realize the tunable frequency band and bandwidth of microstrip filter is a work of great research value. One of the methods of the device. The electric tunable filter based on varactor diode has the advantages of fast electric response, simple bias circuit structure, continuous frequency tuning and low production cost. Electric tunable filter is very popular in the design of electric tunable filter. The emphasis of this paper is also the electric tunable filter based on varactor diode. Firstly, this paper investigates the latest research progress of electric tunable filter. Combined with the design theory and analysis method of microstrip filter, this paper introduces the design theory of electric tunable filter based on the structure of multi-mode resonator. On the basis of this theory, five microstrip filters are designed in this paper. It includes a dual-frequency bandpass filter, a central operating frequency electrically adjustable filter, and a center operating frequency and bandwidth fully adjustable filter. An electrically adjustable filter with adjustable harmonic suppression range is proposed. The center frequency electrically tunable filter is based on the dual-frequency bandpass filter. It is based on the short-circuit branch loaded resonator and a pair of coupled 1/4 wavelength resonators. Compared with the existing electrically tuned filter, the insertion loss of the filter is basically controlled within 5dB at the same time. The relative bandwidth is kept above 10%, which improves the narrow band characteristics of the existing electrically tuned dual-frequency filters. The fully adjustable filters in this paper are based on the step impedance resonator structure. By adjusting the pole, the filter is fully adjustable. Compared with the existing fully adjustable filter, the frequency shift range of the filter reaches 380 MHz. The method of cascading the low pass filter with the cutoff frequency and the electrically adjustable band-pass filter with the center operating frequency is presented in this paper. The filter which can suppress the high order harmonic component of dynamic offset in the electric tunable filter is designed and compared with the existing electric tunable filter. The harmonic suppression range of the filter can move with the central working frequency of the filter, and the high order harmonic component can be suppressed obviously, and the stability of the filter can be improved effectively.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN713

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