【正文】
微帶帶通濾波器的設(shè)計(jì)和實(shí)現(xiàn) 姓 名: 學(xué)號(hào): 院(系) : 機(jī)械與電子信息學(xué)院 專業(yè): 電子信息工程 指導(dǎo)教師: 職稱: 評(píng) 閱 人: 職稱: 2020 年 6 月 摘 要 近幾年隨著商用無(wú)線通信的迅猛發(fā)展,射頻 /微波電路越來(lái)越得到重視和發(fā)展。因此,發(fā)展高性能,研究小型化的帶通濾波器是當(dāng)前非常受關(guān)注的課題。 在 進(jìn)行原理圖設(shè)計(jì)、仿真和優(yōu)化的過(guò)程中,重點(diǎn)內(nèi)容是原理圖的繪制和 S參數(shù)的優(yōu)化。 關(guān)鍵詞: 微帶線 微帶帶通濾波器 仿真軟件 ADS Abstract In recent years, along with the high development of wireless munication in business, Microwave RF circuit has been attracted more and more attention and also got many achievements. At the same time, as one of the important microwave ponents, the microstrip bandpass filters also developed rapidly in recent years. Especially, the microwave BPF directly influences the Performances of the receivers. Bandpass filter namely BPF(bandpass filter) is a device which allow specific frequency range and shield other range. A ideal bandpass filter has a pletely flat passband and the transition should be in a infinitesimal frequency range. Bandpass filter get a wide range of applications in many directions such as wireless munication, image processing and remote sensing. An So, develop high Performance, study miniaturized microwave filter is a hot topic in nowadays. At first, this paper introduces the application of microwave filters, and the current state of studying the filters. Then introduces the theory basis and important parameter. With the software ADS and the formula, this paper also well design a microstrip bandpass filter. At the same time also do the simulation and optimination with the help of ADS. Finally we get a relatively ideal microstrip filter. In the process of designing the schematic diagram, simulating and optimizing, the point is to draw the elementary diagram and optimize parameter S. Based on the formula and diagram known, we can calculate all the parameters of the filter. With that, we can draw the schematic diagram. The optimizing of the parameter S mainly includes the modification of the optimization’ s sphere and its repetition. The filters this design contains are as follows: Pass band , in the belt weakens is smaller than 2dB, the fluctuation is smaller than below above 1dB, and weakens is bigger than 40dB. The experimental shows that microstrip bandpass filter based on microwave circuit simulation software ADS is effective, and the important parameter can be controlled in the required limits. Keywords: microstrip, microstrip bandpass filter, ADS 目 錄 第 1章 引言 .......................................................... 1 167。 帶通濾波器的主要參數(shù) ........................................ 4 167。 奇模和偶模特征阻抗 .......................................... 9 167。 原理圖設(shè)計(jì) ................................................ 14 低通濾波器原型的參數(shù)的計(jì)算 ............................... 14 奇模和偶模特性阻抗的計(jì)算 ................................. 16 微帶線尺寸的計(jì)算 ........................................ 16 原理圖的繪制 ............................................ 18 167。 課題背景和意義 科學(xué)技術(shù)的發(fā)展使得人類社會(huì)進(jìn)入了信息時(shí)代,信息時(shí)代的主要標(biāo)志之一就是信息的快速?gòu)V泛的傳遞。隨著科學(xué)技術(shù)的進(jìn)一步發(fā)展,人類對(duì)通信的需求越來(lái)越高,無(wú)線通信技術(shù)將發(fā)揮越來(lái)越重要的作用。為適應(yīng)這一發(fā)展趨勢(shì),近年來(lái)出現(xiàn)了多芯片組件 (MCM)、片上系統(tǒng) (SOC)、封裝系統(tǒng) (SOP)等新的封裝形式。采用傳統(tǒng)方法設(shè)計(jì)的濾波器尺寸一般比較大,在工作性能上也存在著一定的局限性,往往不能夠滿足現(xiàn)代無(wú)線通信系統(tǒng)的要求,急需從小型化和高性能設(shè)計(jì)兩個(gè)方面進(jìn)行改進(jìn) 。微帶濾波器因?yàn)橹亓枯p、體積小、制造成本低且易于與其他微波電路集成等優(yōu)點(diǎn)而廣泛應(yīng)用在無(wú)線通信系統(tǒng)中 [2]。 近年來(lái),薄膜聲學(xué)體波共振技術(shù)( FBAR)給射頻前端濾波器小型化和集成化帶來(lái)一線曙光。為了減小體積,村田公司開(kāi)發(fā)出 MB 型片式介質(zhì)濾波器,它是由23個(gè)同軸諧振器整塊連體構(gòu)成,而無(wú)需電路基板、耦合器、外罩等。 1990 年日本住友公司提出低溫共燒多層介質(zhì)平面型濾波器的構(gòu)想。在寬帶移動(dòng)化方面, IEEE 802工作組先后制定了WLAN和 WiMAX 等技術(shù)規(guī)范,希望能沿著固定、游牧 /便攜、移動(dòng)這樣的演進(jìn)路線逐步實(shí)現(xiàn)寬帶移動(dòng)化,常用的 WLAN 通信頻段標(biāo)準(zhǔn)為 IEEE ()和 IEEE ()。由于用戶超常規(guī)發(fā)展。制作的微帶濾波器的插損小、帶邊陡峭度高、帶外抑制大、具有高靈敏度和高選擇性,在移動(dòng)通信領(lǐng)域具有廣闊的應(yīng)用前景。 4 第 2 章 帶通 濾波器設(shè)計(jì)理論 論文研究的是使用 ADS 軟件設(shè)計(jì)微帶帶通濾波器的解決方案,而帶通濾波器是以低通濾波器為原型設(shè)計(jì)的。 圖 21 四個(gè)普通濾波器的特性曲線 可以從不同角度對(duì)濾波器進(jìn)行分類: (a)按功能分,有低通濾波器,高通濾波器,帶通濾波器,帶阻濾波器,可調(diào)濾波器。 167。39。139。 c o sc o s1lg10???????? ?????????? ???????? nLA (23) ? ?39。1239。因?yàn)槠浣刂苟赶鳎猿3幙蛇x擇切比雪夫特性曲線而不 取其他的特性曲線。 原型濾波器的元件值的歸一化及其計(jì)算 目的:提高設(shè)計(jì)通用性 歸一化定義: 0g = 39。1? = 1,則其原型元件值可以按下式計(jì)算: