电子与通信技术专业英语Unit-Ⅱ-7课件

UnitⅡElectronicCircuitandItsApplicationLesson7FiltersUnitⅡElectronicCircuitNewWordsfilter[filtə]n.滤波器modify['mɔdifai]vt.更改,修改eliminate[i‘limineit]vt.排除,消除,除去regulation[,reɡju'leiʃən]n.规则,调节,校准crystal['kristəl]n.水晶,结晶,晶体NewWordsceramic[si'ræmik]a.&n.陶器的,陶瓷categorize[‘kætiɡəraiz]v.加以类别,分类bandpass['bændpɑ:s]

n.带通highpassn.高通lowpassn.低通ceramic[si'ræmik]a.&n.PhrasesandExpressions

passivefilter

无源滤波器activefilter

有源滤波器PhrasesandExpressions

Notes1.Afilterisapassiveoractivecircuitdesignedprimarilyforthepurposeofmodifyingasignalorsourceofpower.

滤波器包括无源滤波器和有源滤波器，它们主要是为了改变信号或电源输出而设计的。句中designed…orsourceofpower是过去分词短语，充当定语，修饰circuit。Notes2.Inpowersupply,thefilterisnetworkofcapacitors,resistorandinductsthateliminatestherectifier.

在电源中，滤波器由电容、电阻、与电感组网而成，从而代替了整流器。

⑴isnetworkof相当于consistof，意思是“由……组成”；⑵定语从句thateliminatestherectifier修饰thefilter。2.Inpowersupply,thefilter3.Filterareusedincommunicationspracticetoeliminateenergyatsomefrequencieswhileallowingenergyatotherfrequenciestopasswithlittleornoattenuation.

在通信系统中，滤波器主要用来滤除某些频率成分而允许另一些频率成分无衰减地通过。

⑴不定式toeliminateenergyatsomefrequencies充当主语补足语；

⑵while后接现在分词短语，表示轻微转折。3.Filterareusedincommunica4.Suchfilters,ifpassive,areconstructedusingcapacitors,inductorandsometimesresistors.

句中ifpassive省略了主谓部分，即theyare。4.Suchfilters,ifpassive,ar5.Activefiltersgenerallyutilizeoperationalamplifiers.

句中utilize意为“利用”，相当于use。5.Activefiltersgenerallyuti6.Filterscanbecategorized,intermsoftheirfrequencyresponsecharacteristics,intofourgroups.⑴tocategorizeinto…相当于toclassifyinto…或groupinto…，“把……分成”；

⑵intermsof相当于accordingto。6.Filterscanbecategorized,7.Thehighpassfilterallowsonlythesignalsaboveacertainfrequenciestopass.

高通滤波器只允许高于某个频率的信号通过。句中certain表示某种模糊概念，“某种，某个”。7.Thehighpassfilterallowso8.Somearedesignedtouseatradiofrequencies,whileothersoperateataudiofrequencies.

有的用于射频，有的用于音频。

whileothersoperateataudiofrequencies中省略了aredesignedto，其中while表示轻微转折。8.SomearedesignedtouseatTranslationofTextsLesson7FiltersAfilterisapassiveoractivecircuitdesignedprimarilyforthepurposeofmodifyingasignalorsourceofpower.Apassivefilterrequiresnopowerforitsoperation,andalwayshasacertainamountofloss.Anactivefilterrequiresitsownpower,butmayprovidegain.TranslationofTextsLesson7第7课滤波器滤波器包括无源滤波器和有源滤波器，它们主要是为了改变信号而设计的。无源滤波器不需要电源就可以工作且会有一定的损耗。有源滤波器则需要电源且能提供功率增益。第7课滤波器Inpowersupply,thefilterisnetworkofcapacitors,resistorandinductsthateliminatestherectifier.Agoodpowersupplyfilterwillproduceasmoothdirectcurrentoutputundervariableloadconditions,withgoodregulation.Inpowersupply,the

在电源中，滤波器由电容、晶体管和电感组成，用以消除来自于整流器的直流电流的波动。好的电源滤波器能够在负载可变及好的稳压条件下获得平滑的直流输出电流。在电源中，滤波器由电容、晶体管和电感组成Filterareusedincommunicationspracticetoeliminateenergyatsomefrequencieswhileallowingenergyatotherfrequenciestopasswithlittleornoattenuation.Suchfilters,ifpassive,areconstructedusingcapacitors,inductorandsometimesresistors.Activefiltersgenerallyutilizeoperationalamplifiers(asshowninFig.7-1).Filterareusedinco

在通信系统中，滤波器主要用来滤除某些频率成分而允许另一些频率成分无衰减地通过。如果是无源滤波器，则由电容、电感、晶体管构成；有源滤波器，则由运算放大器构成（如图7-1所示）。在通信系统中，滤波器主要用来滤除某些频率Amplifiersincludedinafilterdesigncanbeusedtoimprovetheperformanceofafilter,whileavoidingtheneedforinductors(whicharetypicallyexpensivecomparedtoothercomponents).Anamplifieralsocanpreventtheloadimpedanceofthefollowingstagefromaffectingthecharacteristicsofthefilter.Anactivefiltercanhavecomplexpolesandzeroswithoutusingabulkyorexpensiveinductor.Theshapeoftheresponse,theQ(qualityfactor),andthetunedfrequencycanoftenbesetwithinexpensivevariableresistors.Amplifiersincluded

在滤波器设计中，放大器可以用来提高滤波器的性能，同时避免了必须使用电感器（这相对于其他组成部分而言通常是昂贵的）。放大器还可以防止下一级负载阻抗对滤波器特性的影响。有源滤波器即使不使用笨重的或昂贵的电感器也可以通过调节廉价的可变电阻器来设置。在滤波器设计中，放大器可以用来提高滤波器Mechanicalfiltersmakeuseoftheresonantpropertiesofcertainsubstances.Crystalandceramicfiltersusepiezoelectricmaterialstoobtainthedesiredfrequencyresponse.Mechanicalfiltersma

机械滤波器由某些具有谐振特性的材料制成，晶体滤波器和陶瓷滤波器采用具有压电特性的材料以获得理想的频率响应。机械滤波器由某些具有谐振特性的材料制成，Filterscanbecategorized,intermsoftheirfrequencyresponsecharacteristics,intofourgroups.Thebandpassfilterallowssignalbetweentwopredeterminedfrequenciestopass,butattenuatesallotherfrequencies.Theband-rejectionorbandstopfiltereliminatesallenergybetweentwofrequencies,andallowssignalsoutsidethelimitfrequenciestopass.Filterscanbecatego

滤波器根据其频率响应特性可分为4种类型。带通滤波器允许两个预定频率之间的信号通过而衰减其他频率的信号。带阻滤波器禁止两个频率之间的信号通过而允许两个频率之外的所有信号通过。滤波器根据其频率响应特性可分为4种类型。Thehighpassfilterallowsonlythesignalsaboveacertainfrequenciestopass.Thelowpassfilerallowsonlythesignalsbelowacertainfrequencytopass.Theactualresponsecharacteristicsofallfourtypesoffilterarehighlyvariable,anddependonmanydifferentfactors.Selectivefilersareemployedinbothtransmittingandreceivingapplications.Somearedesignedforuseatradiofrequencies,whileothersoperateataudiofrequencies.

Thehighpassfiltera

高通滤波器只允许高于某个频率的信号通过，低通滤波器只允许低于某个频率的信号通过。4种滤波器的实际频率特性都是依赖许多不同的因素而变化的。滤波器广泛地用于发射机和接收机，有的用于射频，有的用于音频。高通滤波器只允许高于某个频率的信号通过，Exercises1.WriteT(True)orF(False)besidethefollowingstatementsaboutthetext.Exercisesa.Apassivefilterrequirespowerforitsoperation,andalwayshasacertainamountofloss.b.Anactivefilterrequiresitsownpower,butmayprovidegain.a.Apassivefilterrequirespoc.Inpowersupply,thefilterisnetworkofcapacitors,resistorandinducts.d.Agoodpowersupplyfilterwillproduceasmoothdirectcurrentoutputundervariableloadconditions,withgoodregulation.c.Inpowersupply,thefiltere.Filterisusedincommunicationspracticetoeliminateenergyatsomefrequencieswhileallowingenergyatotherfrequenciestopasswithlittleornoattenuation.f.Suchfilters,ifpassive,areconstructedusingresistors,inductorandsometimescapacitors.e.Filterisusedincommunicatg.Theband-rejectionorbandstopfiltereliminatesallenergybetweentwofrequencies,andallowssignalsoutsidethelimitfrequenciestopass.h.Selectivefilersareemployedinbothtransmittingandreceivingapplications.g.Theband-rejectionorbandst2.Matchthefollowingtermstoappropriatedefinitionorexpression.2.Matchthefollowingtermstoa.afilter1.allowssignalbetweentwopredeterminedfrequenciestopassb.thehighpassfilter2.allowsthesignalsbelowacertainfrequencytopassc.thelowpassfiler3.eliminatesallenergybetweentwofrequenciesd.thebandpassfilter4.allowsthesignalsaboveacertainfrequenciestopasse.theband-rejectionfilter5.apassiveoractivecircuitdesignedprimarilyforthepurposeofmodifyingasignalorsourceofpower.a.afilter3.Fillinthemissingwordsaccordingtothetext.3.Fillinthemissingwordsaca.Afilterisa

or

circuitdesignedprimarilyforthepurposeofmodifyingasignalorsourceofpower.a.Afilterisa