三频微带带通滤波器的研究与设计

发布时间：2018-03-06 05:27

本文选题：三频微带　切入点：阶梯阻抗谐振器　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：在科技日新月异发展的今天,现代无线和移动通信系统以前所未有的速度影响和改善我们的生活的同时,对我们提出更高更迫切的要求。作为通信系统的关键组成部分,具有多频带的射频前端滤波器是实现通信系统多频功能的主要途径。新型无线通信协议如WLAN、WiMAX、LTE、WCDMA等的提出及应用,也使得微型化、插入损耗低、矩形系数高的高性能滤波器成为研究设计的热点。本文研究对象为工作在WLAN和WiMAX频段的三频带通滤波器,并讨论了滤波器设计中常用的谐振器,在此基础上发挥创造力,成功设计出两款微带三频带通滤波器。首先,本文总结了近几年来三频带通滤波器的研究成果,并对多通带滤波器的实现方法进行了简要的介绍。其次,对四分之一波长阶梯阻抗谐振器(SIR)的结构和谐振原理进行了分析,并在此基础上构造出三频滤波器的第一通带。接着简要介绍了开路枝节加载谐振器(OSLR)的结构及其谐振原理,并在此基础上构造双通带滤波器。根据OSLR的奇偶模谐振原理,将奇模谐振响应作为第二通带,偶模谐振响应作为第三通带。为实现系统小型化,将半波长OSLR弯折成“?”形,通过电耦合方式与四分之一波长型SIR耦合,采用0度馈电结构对滤波器进行馈电,实现三个通频带的目的。为改善滤波器的性能,在其输入输出馈电端加载开路枝节线,成功构造出五个衰减大于33dB传输零点,分别位于2.02GHz、2.85GHz、3.01GHz、4.0GHz及5.9GHz处。经过HFSS的优化仿真,在整体尺寸为0.28 0.08g g???的基础上实现三频带功能,其三个通带中心频率分别为2.4GHz、3.5GHz、5.2GHz,插入损耗为0.44dB、0.64dB、0.34dB,3d B相对带宽为11.7%、9.7%、9.1%。最后,对半波长SIR的结构和谐振原理进行了分析,并在此基础上,利用两个C型半波长SIR构造第一、第三通带。用四分之一波长型SIR构造第二通带。将第二通带耦合到第一、第三通带间,达到三频带的目的。用零度馈电结构构造传输零点,获得更好的回波损耗。在整体尺寸为0.214 0.112g g???的基础上实现了滤波器的三频带功能,其三个通带中心频率分别为2.4GHz、3.5GHz和5.2GHz,插入损耗为2.19dB、0.21dB和1.92dB,相对带宽为11.3%、8%和3.5%。
[Abstract]:Today, with the rapid development of science and technology, modern wireless and mobile communication systems affect and improve our lives at an unprecedented speed, while putting forward higher and more urgent demands on us as a key component of the communication system. RF front-end filter with multi-frequency band is the main way to realize the multi-frequency function of communication system. New wireless communication protocols such as WLAN WiMAX / LTEN WCDMA and so on, also make them miniaturized, and the insertion loss is low. High-performance filters with high rectangular coefficients have become a hot topic in the research and design. This paper focuses on three-band pass filters working in the WLAN and WiMAX bands, and discusses the resonators commonly used in the design of filters. Two microstrip three-band pass filters are successfully designed. Firstly, this paper summarizes the research results of three-band pass filters in recent years, and gives a brief introduction to the implementation of multi-pass filters. The structure and resonant principle of 1/4 wavelength stepped impedance resonator are analyzed, and the first pass band of three-frequency filter is constructed. Then, the structure and resonant principle of open-loop loaded resonator OSLR are briefly introduced. According to the odd-even mode resonance principle of OSLR, the odd-mode resonance response is regarded as the second pass band and the even-mode resonant response as the third pass band. In order to realize the miniaturization of the system, the half-wavelength OSLR is bent into "? In order to improve the performance of the filter, an open-circuit branch line is loaded at the input and output feed end to improve the performance of the filter by using the 0-degree feed structure to feed the filter with the 1/4 wavelength SIR. Five attenuation above 33dB transmission 00:00 were successfully constructed at 2.01GHz 4.0GHz and 5.9GHz at 2.02GHz ~ 2.85GHz respectively. The overall size of the transmission is 0.280.08g? ? ? The three-band function is realized on the basis of the three-band function. The three passband center frequencies are 2.4GHz / 3.5GHz and 5.2GHz, respectively, and the insertion loss is 0.44dBN 0.64dBN 0.34dBU / 3dB relative bandwidth is 11.7dB / 9.70.The structure and resonant principle of half-wavelength SIR are analyzed, and the resonant principle is analyzed. Using two C-type half-wavelength SIR to construct the first and third pass band, and using the 1/4 wavelength type SIR to construct the second pass band. The second pass band is coupled to the first and the third pass band to achieve the purpose of three frequency bands. The transmission 00:00 is constructed by using the zero feed structure. A better return loss is obtained. The overall size is 0. 214 0. 1 12 g? ? ? The three bandpass center frequencies are 2.4 GHz and 5.2 GHz, respectively. The insertion loss is 2.19 dB 0.21 dB and 1.92 dB, and the relative bandwidth is 11.3% and 3.5%.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713.5

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