电子专业英语Lesson5Low-passFil.ppt

1、Unit 2 Electronic Circuits,Lesson 5 Low-pass Filters 电子信息工程专业英语教程任治刚 主编 电子工业出版社 ,2020/8/6,电子信息工程专业英语教程,2,Lesson 5 Low-pass Filters,Backgrounds Text tour Language in use Vocabulary Structure Reading/writing techniques,2020/8/6,电子信息工程专业英语教程,3,Terminology DC: Direct Current 直流电 AC: Alternating Current交

2、流电 Laplace transform 拉普拉斯变换 Bode plot 伯德图 transfer function 转移函数 complex plane 复平面 decaying-exponential response 衰减指数响应 quality factor 品质因数,Backgrounds,2020/8/6,电子信息工程专业英语教程,4,Text tour,Outline First-Order Filters A simple RC integrator A simple RC low-pass filter Second-Order Low-Pass Filters An RL

3、C low-pass filter the variables ,2020/8/6,电子信息工程专业英语教程,5,First-Order Filters (1),A simple RC integrator transfer function,Figure 2.1a A simple RC integrator,2020/8/6,电子信息工程专业英语教程,6,First-Order Filters (1),Figure 2.1b A Bode plot of a simple integrator,Bode plot,2020/8/6,电子信息工程专业英语教程,7,First-Order Fi

4、lters (2),Figure2. 2a. A simple RC low-pass filter,A simple RC low-pass filter transfer function,2020/8/6,电子信息工程专业英语教程,8,First-Order Filters (2),Figure 2.2b. The complex function of an RC low-pass filter,The complex function,2020/8/6,电子信息工程专业英语教程,9,First-Order Filters (2),Figure 2.2c. A Bode plot of

5、 a low-pass filter,Bode plot,2020/8/6,电子信息工程专业英语教程,10,Second-Order Low-Pass Filters,Figure2. 3a An RLC low-pass filter,A simple RLC low-pass filter transfer function,2020/8/6,电子信息工程专业英语教程,11,Second-Order Low-Pass Filters,Figure 2.3b A pole-zero diagram of an RLC low-pass filter,pole-zero diagram,202

6、0/8/6,电子信息工程专业英语教程,12,Second-Order Low-Pass Filters,Figure2.4a. The complex function of a second-order low-pass filter (Q = 0.707),2020/8/6,电子信息工程专业英语教程,13,Second-Order Low-Pass Filters,Figure 2.4b The complex function of a second-order low-pass filter (Q = 2),2020/8/6,电子信息工程专业英语教程,14,Vocabulary var

7、iable, transient , order , response, formula, function , factor, origin Structure Reading/writing techniques,Language in use,2020/8/6,电子信息工程专业英语教程,15,Vocabulary,2020/8/6,电子信息工程专业英语教程,16,Variable in dictionary,A quantity that can assume any of a given set of values. Any factor or condition which can

8、be measured, altered, or controlled (e.g. , temperature, pressure, flow, liquid level, humidity, weight, chemical composition, color, etc.). A language object that may take different values, one at a time. Note: The values of a variable are usually restricted to a certain data type. In programming,

9、a character or group of characters that refers to a value and, in the execution of a computer program, corresponds to an address.,2020/8/6,电子信息工程专业英语教程,17,Variable in text,You can easily derive the transfer function as where s is the complex-frequency variable + jand 0 is 1/RC. 传输函数很容易推导出来（公式略）；其中，s

10、是复频率变量 + j，而0等于1/RC。,2020/8/6,电子信息工程专业英语教程,18,Variable in use,variable weather 变化无常的天气 a man of variable character 反复无常的人 variable standards 变化的标准 variable gears 变速齿轮 variable capital 可变资本,2020/8/6,电子信息工程专业英语教程,19,Variable in use,complex variable 复变数 n-dimensional random variable n 维随机变量 normal rand

11、om variable 正态随机变量 real variable 实变量 scalar variable 标量变量 time variable 时间变量,2020/8/6,电子信息工程专业英语教程,20,Transient in dictionary,Passing with time; transitory: 短暂的 Remaining in a place only a brief time: 短期的，临时的 Decaying with time, especially as a simple exponential function of time. 瞬变的 A transient ph

12、enomenon or property, especially a transient electric current. 瞬变现象,2020/8/6,电子信息工程专业英语教程,21,Transient in text,When analyzing transient response using Laplace transforms, we use sL and 1/sC for the impedance of these elements. 在使用拉普拉斯变换分析瞬态响应时，我们用sL和1/sC分别表示电感的阻抗和电容的阻抗。 While the complex frequencys

13、imaginary part (j) helps describe a response to AC signals, the real part () helps describe a circuits transient response. 复频率的虚部有助于描述电路对交流信号的响应，复频率的实部有助于描述电路的瞬态响应。,2020/8/6,电子信息工程专业英语教程,22,Transient in use,damping transient 阻尼瞬变过程 forward switching transient 正向开关瞬态 high-speed transients 快速瞬变现象 init

14、ial transient 起振过渡量, 建起过程值, 初始瞬值 starting transient 起动瞬变(过程)量,2020/8/6,电子信息工程专业英语教程,23,Transient in use,trailing transient 后沿瞬变特性 transition transient 过渡瞬态 turn-off transient 关闭瞬态 turn-on transient 接通瞬态,2020/8/6,电子信息工程专业英语教程,24,Order in dictionary,A condition of logical or comprehensible arrangement

15、 among the separate elements of a group. 顺序 A condition of methodical or prescribed arrangement among component parts such that proper functioning or appearance is achieved: 秩序 Condition or state in general: 情况 The established system of social organization: 体制 Formal written instructions to report f

16、or military duty at a specified time and place. 书面指示,2020/8/6,电子信息工程专业英语教程,25,Order in dictionary,The sum of the exponents to which the variables in a term are raised; degree. 幂次 An indicated number of successive differentiations to be performed. 微分次数 The number of elements in a finite group. 元素个数 T

17、he number of rows or columns in a determinant or matrix. 行或列的数目,2020/8/6,电子信息工程专业英语教程,26,Order in text,A second-order filter provides the variables 0 and Q, which allow us to place poles wherever we want in the complex plane. 二阶滤波器提供了0 和 Q这两个变量，我们可以将极点放置在复平面上任何需要的地方。 As in the first-order case, the

18、second-order low-pass transfer function tends to zero as frequency tends to infinity. 当频率趋近于无穷时，二阶低通滤波器的传输函数趋近于零（和一阶低通滤波器的传输函数一样）。,2020/8/6,电子信息工程专业英语教程,27,Order in use,exponential order 指数序模, 指数级 feeding order 馈给次序 order of equation 方程的次数 order of infinity 无穷大阶 order of magnitudes 数量级 order of matr

19、ix 矩阵的阶,2020/8/6,电子信息工程专业英语教程,28,Order in use,additional order 追加定货 advance order 预订单 bulk order 大宗订单, 大批订货 comparison order 比较指令 derivative order 导数的级 descending order 递减次序, 降序排列,2020/8/6,电子信息工程专业英语教程,29,Response in dictionary,The act of responding. 答复 A reply or an answer. 回复或回答 A reaction, as tha

20、t of an organism or a mechanism, to a specific stimulus. 反应,2020/8/6,电子信息工程专业英语教程,30,Response in text,However, as we can see from Figure 2.1b, the first-order filter does not provide a very selective frequency response. 从图2.1b中，我们也可以看出：一阶滤波器的频率选择特性不是很好。 Now lets examine the second-order functions fr

21、equency response and see how it varies with Q. 现在，让我们考察一下二阶函数的频率响应及其随Q变化的情况。,2020/8/6,电子信息工程专业英语教程,31,amplitude-frequency response 幅度频率响应, 幅频响应曲线 amplitude-phase response 幅度相位响应 complex frequency response 复频响应 flat response 平坦响应(曲线) phase-shift response 相移响应特性 physiological response 生理反应 sinusoidal

22、response 正弦响应, 正弦特性曲线,Response in use,2020/8/6,电子信息工程专业英语教程,32,steady-state response 稳定态(反应)特性; 稳定态灵敏度 step response 瞬态特性, 过渡特性; 阶跃响应 underdamping response 欠阻尼响应 unit function response 单位阶跃函数响应 unit-impulse response 单位脉冲响应 zero input response 零输入响应 zero state response 零状态响应,Response in use,2020/8/6,

23、电子信息工程专业英语教程,33,Formula in dictionary,An established form of words or symbols for use in a ceremony or procedure. 惯用语 An utterance of conventional notions or beliefs; a hackneyed expression. 客套话 A method of doing or treating something that relies on an established, uncontroversial model or approach:

24、 准则，方案 Drinking and driving is a formula for trouble. They proposed a third formula for the new swimming pool.,2020/8/6,电子信息工程专业英语教程,34,Formula in dictionary,A symbolic representation of the composition or of the composition and structure of a compound. 分子式 The chemical formula for water is H2O A pr

25、escription of ingredients in fixed proportion; a recipe. 配方，处方 the secret formula for a new rocket fuel A statement, especially an equation, of a fact, rule, principle, or other logical relation. 公式 formula of integration,2020/8/6,电子信息工程专业英语教程,35,Formula in text,If we think of s as frequency, this f

26、ormula confirms the intuitive feeling that gain is inversely proportional to frequency. 假如把s 当作频率的话，该公式印证了我们有关“增益和频率成反比”的直观推断。,2020/8/6,电子信息工程专业英语教程,36,Formula in use,analysis formula 解析式 approximate formula 近似公式, 近真公式 backward interpolation formula 后向插值公式 Bessels interpolation formula 贝塞尔内插公式 bilin

27、ear formula 双线性公式 binomial formula 二项式定理, 二项式展开式, 二项式公式 Cauchy integral formula 柯西积分公式,2020/8/6,电子信息工程专业英语教程,37,Formula in use,Gaussian distribution formula 高斯分布公式 half-angle formulas 半角公式 identical formula 恒等公式 iterative formula 迭代公式 Poisson integral formula 泊松积分公式 Poissons summation formula 泊松求和公式

28、,2020/8/6,电子信息工程专业英语教程,38,Function in dictionary,The action for which one is particularly fitted or employed. 作用，功能 Assigned duty or activity. 职务，职责 A specific occupation or role: 角色，工作 An official ceremony or a formal social occasion. 重大聚会，庆典,2020/8/6,电子信息工程专业英语教程,39,函数：A mathematical entity whose

29、value, that is, the value of the dependent variable, depends in a specified manner on the values of one or more independent variables, not more than one value of the dependent variable corresponding to each permissible combination of values from the respective range of the independent variables. 功能

30、：A specific purpose of an entity, or its characteristic action. 操作：In data communication, a machine action such as carriage return or line feed. （如回车、换行） 子程序：A subroutine that returns the value of a single variable, and that usually has a single exit, for example, subroutines that compute mathematic

31、al functions, such as sine, cosine, logarithm, or that compute the maximum of a set of numbers.,Function in dictionary,2020/8/6,电子信息工程专业英语教程,40,Function in text,As before, Figure 2.4a shows the function as a curved surface, depicted in the three-dimensional space formed by the complex plane and a ve

32、rtical magnitude vector. 图2.4a以曲面图的形式展示了（频率响应）函数，该曲面图是在由复频面和垂直幅度向量构成的三维空间中绘制的。,2020/8/6,电子信息工程专业英语教程,41,Function in use,function duty office role The central meaning shared by these nouns is the actions and activities assigned to, required of, or expected of a person. the function of a teacher 老师的作用

33、 a bank clerks duty 银行职员的职责 assumed the office of financial adviser 担任财政顾问这个职务 the role of a parent 父母的职责,2020/8/6,电子信息工程专业英语教程,42,normal probability function 概率正态分布函数 orthonormal function 正交函数 self-correlation function 自相关函数 trigonometrical function 三角函数 unbounded function 无界函数 unit step function 单

34、位阶跃函数 zero Bessel function 零次贝塞尔函数 function of first degree 一次函数 function of many variables 多元函数 function of random variable 随机变量函数,Function in use,2020/8/6,电子信息工程专业英语教程,43,Factor in dictionary,One that actively contributes to an accomplishment, a result, or a process 因素 One who acts for someone els

35、e; an agent. 代理人 A person or firm that accepts accounts receivable as security for short-term loans 代理商，经纪人 One of two or more quantities that divides a given quantity without a remainder 因子 2 and 3 are factors of 6; a and b are factors of ab. A quantity by which a stated quantity is multiplied or d

36、ivided, so as to indicate an increase or decrease in a measurement 系数 The rate increased by a factor of ten.,2020/8/6,电子信息工程专业英语教程,44,Factor in text,The second-order function decreases twice as fast, however, because of the s2 factor in the denominator. 二阶低通滤波器的下降速度是一阶低通滤波器的两倍，这是其分母中出现 s2 因子的缘故。,202

37、0/8/6,电子信息工程专业英语教程,45,Factor in use,Duty actor 负载比, 占空系数; 占空比 Equation factor 换算率 Fidelity factor 保真度, 重现率, 传真度 Greatest common factor 最大公因数 Prime factor 素因数, 素因子 Scale factor 标度因子,比例系数,定标因数,2020/8/6,电子信息工程专业英语教程,46,Factor in use,Transfer factor 传输系数, 转移因子 Transport factor (半导体)迁移率, Twiddle factor 旋

38、转因子 Utilization factor 设备利用率 Voltage regulation factor 电压调整系数 Weighting factor 权重因数 Factor of the order 数量级,2020/8/6,电子信息工程专业英语教程,47,Origin in dictionary,The point at which something comes into existence or from which it derives or is derived. 起源 Ancestry: 出身，血统： The fact of originating; rise or derivation: 起源 The point of intersection of coordinate axes, as in the Cartesian coordinate system. 原点,2020/8/6,电子信息工程专业英语教程,48,Origin in text,Varying 0 changes the poles distance from the origin.