宽阻带微带低通滤波器的设计与研究

电子科技大学
注 1：注明《国际十进分类法 UDC》的类号。
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DESIGN AND RESEARCH OF WIDE STOPBAND MICROSTRIP LOW-PASS FILTER
A Master Thesis Submitted to University of Electronic Science and Technology of China
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摘要
关键词：微带滤波器，宽阻带，高低阻抗，缺陷地结构，发卡式
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ABSTRACT
ABSTRACT
Microwave filter is one of the most important devices in microwave circuit, whose filtering characteristics directly affect the operation of the entire microwave circuit system. And now, the bandwidth of microwave resources are divided more and more fine. The wide application of handheld mobile devices also requires high performance, miniaturization, low cost microwave device. And microstrip filter becomes one of the main forms of microwave filter because of its high-performance, easy-to-manufacture, small size and low cost. Microwave low-pass filter is usually used in the front of the circuit system, used to isolate the high frequency signal and protect the circuit back of it. People always wish it has a steep attenuation and enough wide stopband scope, therefore, high performance, wide stopband is becoming a hot spot of current research on microwave low-pass filte. In this thesis, the mainly effort is the design theory and technology of the high performance wide stopband microstrip low-pass filter, including stepped-impedance resonator filter(SIR), DGS structure low pass filter and hairpin filter. The mainly work of this thesis includes: First of all, the technologies about microstrip filter have been summarized, which is based on consult a vast amount of domestic and international literature. Then a detail study on the technological achievements of broadening the stopband has been carrdesigning a microstrip filter has been introduced, including the detailed process how to convert the normal lumped low-pass filter to microstrip filter using Richards transform ， Kuroda rules and stepped-impedance resonator equivalent method. Thirdly, the design results of microstrip low-pass filter used DGS structure has been introduced. Then a detail study on the classic dumbbell DGS structure, which equivalent circuit is extracted , is carried out. And a serpentine aperture DGS structure is put forward, which increases the equivalent capacitance of the circuit and results in lower attenuation frequency and more steep slope of the stopband characteristics.
Major: Author: Advisor: School :
Measurement Technology and Instruments Xujing Lv
Kaiyu Qin School of Aeronautics and Astronautics
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独创性声明
本人声明所呈交的学位论文是本人在导师指导下进行的研究工 作及取得的研究成果。据我所知，除了文中特别加以标注和致谢的地 方外，论文中不包含其他人已经发表或撰写过的研究成果，也不包含 为获得电子科技大学或其它教育机构的学位或证书而使用过的材料。 与我一同工作的同志对本研究所做的任何贡献均已在论文中作了明 确的说明并表示谢意。
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ABSTRACT
Fourthly, the method of design a wide stopband low-pass filter, using stepped-impedance and the HFSS. Finally ， a elliptic low-pass filter with rapid decay and wide stopband characteristics has been achieved. On one hand, the tandem structure is transformed into microstrip filter using stepped-impedance resonator equivalent, and adds the interdigital structure to expand its stopband; On the other hand, parallel structure is directly equivalent to the hairpin resonator structure. Then a low pass filter is designed by the way of cascading the hairpin structure. Finally a modification with S-shaped slit hairpin structure was proposed which has a lower resonant frequency and steeper attenuation edge. Keywords: microstrip filter, wide stopband, SIR, DGS, hairpin resonator equivalent, has been detailed studied. and a stepped-impedance low pass filter with wide stopband has been simulated in the ADS
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目录
目
录
第一章 绪
论........................................................ 1
1.1 研究背景及意义 .............................................. 1 1.2 国内外研究现状 .............................................. 3 1.3 本论文的结构安排 ............................................ 4 第二章 微带滤波器理论基础 ............................................ 6 2.1 滤波器理论基础 .............................................. 6 2.1.1 滤波器的分类 .......................................... 6 2.1.2 滤波器的基本参数 ...................................... 7 2.1.3 低通滤波器的归一化原型 ................................ 7 2.2 低通滤波器的微带实现 ....................................... 11 2.2.1 Richards 变换与 Kuroda 规则 ............................ 11 2.2.2 高低阻抗线等效原理 ................................... 13 2.3 本章小结 ................................................... 15 第三章 DGS 结构在微带滤波器中的应用 ................................. 17 3.1 常见 DGS 结构介绍 ........................................... 17 3.1.1 哑铃型 DGS 结构及其变形结构 ........................... 17 3.1.2 螺旋型的 DGS 结构 ..................................... 19 3.1.3 其他形状 DGS 结构 ..................................... 20 3.2 哑铃型 DGS 结构的等效电路和参数分析 ......................... 21 3.2.1 哑铃型 DGS 等效电路提取 ............................... 21 3.2.2 哑铃型 DGS 结构参数分析 ............................... 22 3.3 蛇形缝隙 DGS 结构 ........................................... 24 3.4 本章小结 ................................................... 25 第四章 高低阻抗低通滤波器的设计 ..................................... 27 4.1 高低阻抗线等效法设计低通滤波器 ............................. 27 4.1.1 在 ADS 中的设计与优化仿真 ............................. 29 4.2 调节高低阻抗比值对频率响应的影响 ........................... 31 4.2.1 调节低阻抗线对寄生通带的影响 ......................... 31