基于ADS的带阻滤波器设计.doc

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1、电磁波与微波技术课程设计-带阻滤波器的设计与仿真 课 题：带阻滤波器的设计与仿真 指导老师： 姓 名： 学 号： 目 录1. 设计要求32. 微带短截线带阻滤波器的理论基础32.1 理查德变换42.2 科洛达规则63. 设计步骤73.1 ADS 简介73.2 初步设计过程83.3 优化设计过程143.4 对比结果174. 心得体会175. 参考文献181课程设计要求：1. 1 设计题目：带阻滤波器的设计与仿真。1.2 设计方式：分组课外利用ads软件进行设计。1.3 设计时间：第一周至第十七周。1.4 带阻滤波器中心频率：6GHz；相对带宽：9%；带内波纹： 25dB；在频率5.5GHz和6.

2、5GHz处， 衰 减3dB；输入输出阻抗：50。2微带短截线带阻滤波器的理论基础 当频率不高时，滤波器主要是由集总元件电感和电容构成，但当频率高于500Mz时，滤波器通常由分布参数元件构成，这是由于两个原因造成的，其一是频率高时电感和电容应选的元件值小，由于寄生参数的影响，如此小的电感和电容已经不能再使用集总参数元件；其二是此时工作波长与滤波器元件的物理尺寸相近，滤波器元件之间的距离不可忽视，需要考虑分布参数效应。我们这次设计采用短截线方法，将集总元件滤波器变换为分布参数滤波器，其中理查德变换用于将集总元件变换为传输段，科洛达规则可以将各滤波器元件分隔。2.1 理查德变换 通过理查德变换，可以

3、将集总元件的电感和电容用一段终端短路和终端开路的传输线等效。终端短路和终端开路传输线的输入阻抗具有纯电抗性，利用传输线的这一特性，可以实现集总元件到分布参数元件的变换。在传输线理论中，终端短路传输线的输入阻抗为： = （1.0）式中 当传输线的长度 = 时 （1.1）将式（1.1）代入式（1.1），可以得到 （1.2） 式中 （1.3）称为归一化频率。终端短路的一段传输线可以等效为集总元件电感，等效关系为 （1.4）式中S = j （1.5）称为理查德变换。同样，终端开路的一段传输线可以等效为集总元件的电容。终端开路传输线的输入导纳为 （1.6）式中 S = j 为理查德变换。 前面将电感和电

4、容用一段传输线等效时，传输线的长度选择为 ，这样的选择有个好处，因为点f = S = j = j1 （1.7）这适合将集总元件低通滤波器原型转换为由传输线构成的低通滤波器，这时低通滤波器原型的电感值与终端短路传输线的归一化特性阻抗值相等，低通滤波器原型的电容值与终端开路传输线的归一化特性导纳值相等。 当传输线的长度 时，这种选择适合将集总元件低通滤波器原型转换为由传输线构成的带阻滤波器。所以我们在做设计时用的传输线的长度 为 。2.2 科洛达规则科洛达规则是利用附加的传输线段，得到在实际上更容易实现的滤波器。利用科洛达规则既可以将串联短截线变换为并联短截线，又可以将短截线在物理上分开。附加的传

5、输线段称为单位元件。3 设计步骤 3.1 ADS简介 ADS（Advanced Design System）电子设计自动化软件为美国Agilent Technologies公司的产品，该软件的功能包含时域电路模拟（SPICElike Simulation）、频域电路模拟（HarmonicBalance Linear Analysis）、电磁模拟（EM Simulation）、通信系统模拟（Communication SystemSimulation）、数字信号处理设计（DSP）等。此外和多家芯片厂商合作建立ADS Design Kit及Model File供设计人员使用。使用者可以利用Desi

6、gn Kit及软件模拟功能进行通信系统的设计、规划与评估，以及MMICRFIC、类比与数位电路设计。除上述的设计模拟功能外，ADS也提供辅助设计功能，如Design Guide是以范例及指令方式示范电路或系统的设计规划流程，而Simulation Wizard是以步骤式界面进行电路设计与分析。ADS还能提供与其他设计模拟软件（如SPICE、Mentor Graphics的ModelSim、Cadence的NC-Verilog、Mathworks的MATLAB等）做CoSimulation，加上丰富的元件应用模型库及量测验证仪器间的连接功能，将增加电路与系统设计的方便性、速度与精确性。它提供优秀

7、的频率模式和混合模式电路仿真器，可以模拟整个通信信号通路，完成从电路到系统的各级仿真。它把广泛的经过验证的射频、混合信号和电磁设计工具集成到一个灵活的环境中。ADS采用自顶至底的设计和自底至顶的验证方法，将系统设计和验证时间降到最少。它具有DSP、RF和EM协同仿真能力，从而能在系统级设计中高效率地分配和优化系统性能。完成系统建模后，就可用实际RE和DSP电路设计替代行为模型，评估它们对性能的影响。当任何一级仿真结果不理想时，都必须回到原理图中重新进行优化，并再次进行仿真，直到仿真结果满意为止，这样可以保证实际电路与仿真电路的一致性。ADS可以为电路设计者提供进行模拟、射频与微波等电路和通信系

8、统设计的仿真分析方法，其提供的仿真分析方法大致可以分为时域仿真、频域仿真、系统仿真和电磁仿真。3.2 初步设计过程利用微带短截线带阻滤波器的理论基础，可以方便地设计出符合技术指标的微带短截线滤波器。下面我们用ADS设计并仿真微带短截线带阻滤波器的原理图，。微带短截线带阻滤波器的设计指标如下：中心频率：6GHz；相对带宽：9%；带内波纹： 25dB；在频率5.5GHz和6.5GHz处， 衰减3dB；输入输出阻抗：50。 3.2.1创建原理图启动ADS软件创建一名为Filter_Stubl的原理图。3.2.2 利用ADS的工具tools完成对微带线的计算利用ADS提供的工具tools，可以进行微带

9、线物理尺寸和电参数之间的数值计算，若给定微带线的特性阻抗和电长度，可以计算微带线的宽度。（1） 设置微带线参数。 在【Microstrip Substrate】对话框中进行设置，设置好后在原理图中有：（2） 在微带线元件面板上，选择一个微带线MLIN，插入原理图的画图区。（3） 在画图区中选中微带线MLIN,再选择【tools】调出【LineCalc】计算窗口。（4） 在【LineCalc】计算窗口，设置：将频率Freq 设置为 6 GHz将微带线的特性阻抗设置为 70.7 Ohm将微带线的长度相移设置为 90度点击【Synthesize】按钮可计算出 微带线的宽度 W =1.458mm 和微

10、带线的长度 L = 8.457mm 。（5） 在【LineCalc】计算窗口，继续计算将频率Freq 设置为 6 GHz将微带线的特性阻抗设置为 50 Ohm点击【Synthesize】按钮可计算出微带线的宽度 W = 2.647mm（6） 在原理图画图区中，计算终端开路的微带线MLOC.（7） 在【LineCalc】计算窗口，设置：将频率Freq 设置为 6 GHz将微带线的特性阻抗设置为 170.7 Ohm将微带线的长度相移设置为 90度点击【Synthesize】按钮可计算出 微带线的宽度 W = 0.093mm 和微带线的长度 L =9.133mm 。（8） 在【LineCalc】计算

11、窗口，继续计算将频率Freq 设置为 6 GHz将微带线的特性阻抗设置为 60.4 Ohm将微带线的长度相移设置为 90度点击【Synthesize】按钮可计算出微带线的宽度 W = 1.940mm和微带线的长度 L =8.455mm 。（9） 通过上述计算得到的数据，是微带短截线带阻滤波器的尺寸。3.2.3 设计原理图（1）保留前面设置的微带线参数，删除原理图中的一个微带线MLIN。（2）在原理图的元件面板列表上，选择微带线【Tlines-Microstrip】元件面板上出现与微带线对应的元件图标。在微带线元件面板上，选择微带线MLIN，4次插入到原理图中，并做如下设置： （3）在微带线元件

12、面板选择微带线的T形结MTEE，3次插入到原理图中，并做如下设置： （4）在微带线元件面板，选择终端开路的微带线MLOC,3次插入原理图中，并做如下设置： （5）在S参数仿真元件面板上，选择负载终端Term，2次插入原理图中，并让两个负载均接地。（6）应用连接工具，将MTEE , MLOC，Term和 MLIN 相连如下图： 3.2.4 原理图仿真（1）在S 参数仿真元件面板上，选择S参数仿真控件SP,插入到原理图中，并设置如下： （2）对微带短截线带阻滤波器的原理图仿真。 （3）数据显示，结果如下： （4）对比设计指标发现此设计在多个方面存在不足，如：中心频率没有正好落在6GHz，M1和M2

13、点的衰减又过大3.3 优化设计过程 （1）由于3.2.4（3）图中曲线不满足技术指标，需要调整原理图，下面采用优化方法调整原理图。在优化仿真之前，先设置变量，然后再添加优化控件和目标控件。 （2） 修改S参数仿真控件中微带线段的取值方式，将微带线段导体带的宽度W设置为变量。再对原理图中TL2和TL3进行设置如下：TL2 的导体宽度设置为 W = x1 mmTL3的导体宽度设置为 W = x1 mm （3）设置T形结Tee1，Tee2，Tee3如下（单位mm）：Tee1 设置为 W1=2.647 W2=x1 W3=x2Tee2 设置为 W1=x1 W2=x1 W3=x3Tee3 设置为 W1=x

14、1 W2=x2.647 W3=x2 （4）设置终端开路的微带线MLOC 如下：微带线TL5的宽度设置为 W = x2 mm微带线TL6的宽度设置为 W = x3 mm微带线TL7的宽度设置为 W = x2 mm （5）在原理图的工具栏，选择变量【var】按钮，插入原理图中，双击VAR，打开【Variables and Equations】对话框，在对话框中分别对x1，x2，x3进行设置 其结果如下：（6）在原理图的元件面板列表上，选择优化元件【Optim/Stat./yield/DOE】项，在优化的元件面板上，选择优化控件Optim插入原理图的画图区，并选择目标控件Goal插入原理图的画图区，

15、共4个。 （7）双击Optim ，打开【Nominal Optimization】窗口，在其中设置优化控件，设置优化控件的步骤如下： 选择随机Random 优化方式 优化次数 400 次，其余保持默认状态。（9） 分别设置Goal1，Goal2，Goal3，Goal4 控件，结果如下： （10） 点击仿真【Simulate】图标，运行仿真，等仿真结束后，选【Simulate/Update Optimization Values】命令，将优化后的值保存在原理图中。（11） 数据结果显示： 3.4 对比结果查看优化后的曲线图可知： 在5.5GHz 处， 在 6 GHz 处， 在 6.6GHz处，

16、这组数据比起优化前的要好的多了，以上数据满足了设计要求的技术指标。 4 心得体会待添加的隐藏文字内容3 这次课程设计总的来说不是特别容易，在课堂上虽然学了不少的理论知识，可当真正实践的时候就发现自己懂的太少了，这次的仿真软件完全是自学的，自己图书馆查资料，上网找资料，在查找和阅读中确实学到挺多知识，也对ADS的仿真过程以及带阻滤波器的原理有了更深刻的理解，在设计过程中遇到不少的问题，但都在我们组员的共同努力下找到解决办法，大家共同努力，共同进步，通过这次课程设计更加体会到实践对于理论的重要性，平时基本都是上课，实践的机会很少，以后应该加强这方面的练习。5.参考文献1. 电磁场与微波技术 -人民

17、邮电出版社2. 射频电路理论与设计-人民邮电出版社 3. ads应用详解 -人民邮电出版社4. 网络所搜Employment tribunals sort out disagreements between employers and employees.You may need to make a claim to an employment tribunal if: you dont agree with the disciplinary action your employer has taken against you your employer dismisses you and y

18、ou think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, seeDismissal.You can make a claim to an employment tribunal, even if you haventappealedagainst the disciplinary action your employer has taken against you. However, if you win your case, the tri

19、bunal may reduce any compensation awarded to you as a result of your failure to appeal.Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are complaining about happened. If your application is received after this time

20、 limit, the tribunal will not usually accept i.If you are worried about how the time limits apply to you, take advice from one of the organisations listed underFurther help.Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence

21、 under an oath or affirmation.Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the organisations listed underFurther help.If you are being represented by a solicito

22、r at the tribunal, they may ask you to sign an agreement where you pay their fee out of your compensation if you win the case. This is known as adamages-based agreement. In England and Wales, your solicitor cant charge you more than 35% of your compensation if you win the case.If you are thinking ab

23、out signing up for a damages-based agreement, you should make sure youre clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by e-mail, click onnearest

24、 CAB.For more information about making a claim to an employment tribunal, seeEmployment tribunals.The (lack of) air up there Watch mCayman Islands-based Webb, the head of Fifas anti-racism taskforce, is in London for the Football Associations 150th anniversary celebrations and will attend Citys Prem

25、ier League match at Chelsea on Sunday.I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport.For me its about how he felt and I would like to speak to him first to find out what his experience was.Uefa hasopened disciplinary proceedings against CSKAfor the raci

26、st behaviour of their fans duringCitys 2-1 win.Michel Platini, president of European footballs governing body, has also ordered an immediate investigation into the referees actions.CSKA said they were surprised and disappointed by Toures complaint. In a statement the Russian side added: We found no

27、racist insults from fans of CSKA.Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day; May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very m

28、essy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字开头的年龄已经到了尾声。或许是愧疚于自己似乎把转瞬即逝的很多个不同的日子过成了同一天的样子；或许是追溯过去，对自己那些近乎偏执的怪异信念的醒悟，这些天以来，思绪一直很凌乱，在脑海中不断纠缠。总觉得自己自己似乎应该去做点什么，或者写点什么。二十年的

29、人生轨迹深深浅浅，突然就感觉到有些事情，非做不可了。The end of our life, and can meet many things really do?而穷尽我们的一生，又能遇到多少事情是真正地非做不可？During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional; Junior high school

30、, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isnt really grow up, it seems is not so important; Then in high school, think dont want to give vent to out your inner voice can be in the high schoo

31、l children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already cant remember his appearance.童年时，觉得压岁钱和新衣服是过年必备，但是随着年龄的推进，会越来越

32、发现，那些东西根本就可有可无；初中时，以为要有一场暗恋才意味着真正的成长，但三年过去后，自己心平气和的写同学录的时候，突然就发现是不是真正的成长了，好像并没有那么重要了；然后到了高中，觉得非要吐露出自己的心声才能为高中生涯里的懵懂情愫划上一个句点，但毕业晚会的时候最终还是被梗塞在了咽喉，后来再次站在他曾经挥汗如雨的球场，看着他投过篮球的球框时，突然间发现自己已经想不起他的容颜。Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, an

33、d time.原来，这个世界上，对某个事件能产生化学反应的，除了非做不可的坚决，还有，时间。A persons time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there

34、are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritual.一个人的时候，自己的想法总是特别地清晰。想要的，不想要的，界限明确，好像没有什么可以撼动自己。也曾经好像已经下定了决心去做某件事，但更多的时候是最后又打起了退堂鼓。嫌恶过自己的怯懦，最终却发现有很多缘分，有很多错过，好像冥冥之中真的

35、已经注定。那些曾经所谓的非做不可，只是青葱年华里自己给自己注射的一支强心剂，或者说，是自以为是的精神寄托罢了。At the moment, the sky is dark, the air is fresh factor after just rained. Suddenly thought of blue plaid shirt; Those were broken into various shapes of stationery; From the corner at the beginning of deep friendship; Have declared the end of t

36、he encounter that havent start planning. Those years, those days of do, finally, like youth, will end in our life.此刻，天空是阴暗的，空气里有着刚下过雨之后的清新因子。突然想到那件蓝格子衬衫；那些被折成各种各样形状的信纸；那段从街角深巷伊始的友谊；还有那场还没有开始就宣告了终结的邂逅计划那些年那些天的非做不可，终于和青春一样，都将在我们的人生中谢幕。Baumgartner the disappointing news: Mission aborted. r plays an imp

37、ortant role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weat

38、her lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of tur

39、bulence.The supersonic descent could happen as early as Sunda.The weatheThe balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth becomes the concrete bottom of a swimming p

40、ool that he wants to land on, but not too hard. Still, hell be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound

41、- 690 mph (1,110 kph) - in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him completely.If he goes too fast or spins out of control, he has a stabilization parachute that can be

42、deployed to slow him down. His team hopes its not needed. Instead, he plans to deploy his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).In order to deploy this chute successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachute that will open automatically if he loses consciousness at mach speeds.Even if everything goes as planned, it wont. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).cause there