Lesson11Filter电子技术专业英语教程.ppt

Lesson 11 Filter 电子技术专业英语教程冯新宇 主编 电子工业出版社 ,Unit 4 Power,2019/5/4,电子技术专业英语教程,2,Lesson 11 Filter,Backgrounds Text tour Language in use Vocabulary Structure Reading/writing techniques,2019/5/4,电子技术专业英语教程,3,Terminology Electronic filters IIR filter FIR filter,Backgrounds,2019/5/4,电子技术专业英语教程,4,Terminology,2019/5/4,电子技术专业英语教程,5,lowpass filter 低通滤波器 bandpass filter 带通滤波器 bandstop filter 带阻滤波器 frequency responses 频率响应,2019/5/4,电子技术专业英语教程,6,Electronic filters,Electronic filters are electronic circuits which perform signal processing functions, specifically to remove unwanted frequency components from the signal, to enhance wanted ones, or both. Electronic filters can be: passive or active analog or digital high-pass, low-pass, bandpass, band-reject (band reject; notch), or all-pass. discrete-time (sampled) or continuous-time linear or non-linear infinite impulse response (IIR type) or finite impulse response (FIR type),2019/5/4,电子技术专业英语教程,7,Electronic filters,The most common types of electronic filters are linear filters, regardless of other aspects of their design.,2019/5/4,电子技术专业英语教程,8,IIR filter,IIR filters may be implemented as either analog or digital filters. In digital IIR filters, the output feedback is immediately apparent in the equations defining the output. Note that unlike with FIR filters, in designing IIR filters it is necessary to carefully consider “time zero“ case in which the outputs of the filter have not yet been clearly defined.,2019/5/4,电子技术专业英语教程,9,FIR filter,A finite impulse response (FIR) filter is a type of a digital filter. The impulse response, the filters response to a Kronecker delta input, is finite because it settles to zero in a finite number of sample intervals. This is in contrast to infinite impulse response (IIR) filters, which have internal feedback and may continue to respond indefinitely. The impulse response of an Nth-order FIR filter lasts for N+1 samples, and then dies to zero.,2019/5/4,电子技术专业英语教程,10,Outline Brief introduction (para.1-6) Lowpass Filters (para.7-8) Highpass Filters (para.9-10) Bandpass Filters (para.11- 13) Bandstop Filters (para.14- 15),Text tour,2019/5/4,电子技术专业英语教程,11,Brief introduction,A filter can have a lowpass, highpass, bandpass, or bandstop response can also be described by the method used to approximate the ideal filter a filters primary purpose is to differentiate between different bands of frequencies hertz (Hz) or radians/second gain characteristics of the passband(s) and stopband(s) of the filter response.,2019/5/4,电子技术专业英语教程,12,Lowpass Filters,four parameters: the passband gain apass, the stopband gain astop, the passband edge frequency fpass, and the stopband edge frequency fstop limit the high-frequency content of a signal,2019/5/4,电子技术专业英语教程,13,Highpass Filters,eliminate low frequencies from a signal,2019/5/4,电子技术专业英语教程,14,pass a band of frequencies while attenuating frequencies above or below that band. load. the processing of voice signals,Bandpass Filters,2019/5/4,电子技术专业英语教程,15,Bandstop Filters,a 60Hz notch filter used in sensitive measurement equipmen,2019/5/4,电子技术专业英语教程,16,Vocabulary attenuation ,amplitude ,decibel , passband,ripple, stress Structure,Language in use,2019/5/4,电子技术专业英语教程,17,Vocabulary,2019/5/4,电子技术专业英语教程,18,the act of attenuating or the state of being attenuated the loss of energy suffered by radiation as it passes through matter, esp as a result of absorption or scattering,attenuation in dictionary,2019/5/4,电子技术专业英语教程,19,attenuation in text,For example, a lowpass filter would pass low frequencies with little attenuation (reduction in amplitude), while high frequencies would be significantly reduced. 举例来说，一个低通滤波器允许频率衰减很小的低频信号通过（主要是振幅的衰减），然而对高频信号来说，则会产生一个显著的减小。,2019/5/4,电子技术专业英语教程,20,attenuation q 衰减q attenuation coeffcient 衰减系数 speed attenuation 转速衰减 attenuation features 衰减特征 attenuation zone 衰减区 paid attenuation 单调衰减 height attenuation 高衰减 attenuation equalizers 衰减均衡器 non attenuation 非衰减,attenuation in use,2019/5/4,电子技术专业英语教程,21,greatness of extent; magnitude 广阔, 广大 abundance or copiousness充足, 丰富 breadth or scope, as of the mind (思想的)广度 the angular distance along the horizon measured from true east or west to the point of intersection of the vertical circle passing through a celestial body(天体)出没(磁)方位角 the maximum variation from the zero or mean value of a periodically varying quantity (起重机)作用半径 (交变电流的)幅度, (无线电波的)波幅; 调幅 (音波场中空气压力的)振幅, (钟摆持的)摆幅 (生物的类或群的)生态适应范围 射程,amplitude in dictionary,2019/5/4,电子技术专业英语教程,22,amplitude ratio 振幅比 amplitude anomalies 振幅异常 amplitude transformer 变幅杆 amplitude subdivision 幅值细分 instantaneous amplitude 瞬时振幅 large amplitude 大振幅 signal amplitude 信号幅度 voltage amplitude 电压幅值 amplitude modulator 调幅器 amplitude functions 振幅函数,amplitude in use,2019/5/4,电子技术专业英语教程,23,a unit for comparing two currents, voltages, or power levels, equal to one tenth of a bel a similar unit for measuring the intensity of a sound. It is equal to ten times the logarithm to the base ten of the ratio of the intensity of the sound to be measured to the intensity of some reference sound, usually the lowest audible note of the same frequency,decibel in dictionary,2019/5/4,电子技术专业英语教程,24,As we can see, the values in decibels are more manageable for very small gains. Some filter designers prefer to use attenuation (or loss) values instead of gain values. 可以看到，对非常小的增益来说分贝值都可控。,decibel in text,2019/5/4,电子技术专业英语教程,25,db decibel 分贝 decibel unit 分贝单位 decibel chart 分贝图 decibel loss 分贝衰减,decibel in use,2019/5/4,电子技术专业英语教程,26,通(频)带, 滤波传输波段, 滤波通带,passband in dictionary,2019/5/4,电子技术专业英语教程,27,The passband extends from zero frequency (dc) to the passband edge frequency fpass, and the stopband extends from the stopband edge frequency fstop to infinity. 该通带频率取值从零频（直流）到通带边缘频率fpass，阻带边缘频率取值从阻带缘频率fstop至无限远。,passband in text,2019/5/4,电子技术专业英语教程,28,passband response 通带响应 passband flattening 通带平坦化 filter passband 滤波器通带 parasitic passband 寄生通带 passband sampling 带通采样 passband signal 通带信号 received passband 接收通带 pass band width 通带宽度,passband in use,2019/5/4,电子技术专业英语教程,29,n a slight wave or undulation on the surface of water a small wave or undulation in fabric, hair, etc a sound reminiscent of water flowing quietly in ripples an oscillation of small amplitude superimposed on a steady value,ripple in dictionary,2019/5/4,电子技术专业英语教程,30,vb to form ripples or flow with a rippling or undulating motion to stir up (water) so as to form ripples to make ripple marks,ripple in dictionary,2019/5/4,电子技术专业英语教程,31,Most notably, the absence or presence of ripple (variations) in the passband and stopband clearly set one approximation method apart from another. 最显著的区别是通带和阻带中纹波（变化）的存在与否，能把一种逼近方法与另一种方法区分开。,ripple in text,2019/5/4,电子技术专业英语教程,32,vibration ripple 振动波纹 voltage ripple 电压纹波 ripple structure 波纹结构 ripple analysis 纹波分析 ripple metal 波纹金属 pressure ripple 压力脉动 ripple ratio 纹波系数 elastic ripple 弹性波纹,ripple in use,2019/5/4,电子技术专业英语教程,33,n special emphasis or significance attached to something mental, emotional, or physical strain or tension emphasis placed upon a syllable by pronouncing it more loudly than those that s