滤波器外文原文及翻译

Thisinventionrelatestomechanicalwavefiltersandmoreparticularlytothosewhichcompriseoneormoretransversemembersadaptedforflexuralvibration.Anobjectoftheinventionistoreducetheminimumwidthoftransmissionbandobtainableinamechanicalwavefilterwhichemploysatransverseflexuralvibratorymember.Otherobjectsoftheinventionaretosimplifythemechanicalstructureandreducethecostoffiltersofthistype.Oneformofmechanicalwavefiltercomprisesacentralrodofacousticmaterialandoneormorecentrallylocatedtransversemembersadaptedtobesetintoflexuralvibrationwhenlongitudinalvibrationsareimpresseduponanendoftherod.Foragivenrod,thewidthofthetransmissionbanddecreasesasthemassofthetransversemembersisincreased.Peaksofattenuationoccurattheantiresonantfrequenciesofthetransversemembers,andthesepeaksareusuallylocatedclosetothebandlimitstoobtainsharpcut-offs.Heretofore,thetransversemembershavebeenmadeintheformofcrossbars.Theflexuralantiresonanceofabarisdirectlyproportionaltoitswidthandinverselyproportionaltothesquareofitslength.Sincetheantiresonantfrequencyisfixed,toincreasethemass,andtherebynarrowtheband,thewidthofthebarmaybeincreasedbyafactorKanditslengthincreasedatthesametimebythesquarerootofK.However,apointisreachedatwhichtheratioofthewidthtothelengthissolargethatthebarwillnolongervibratesatisfactorilyintheflexuralmode.Thereis,therefore,afairlydefinitelimitontheminimumbandwidthobtainablewithfiltersusingcrossbars.Inaccordancewiththepresentinventionthislimitationonminimumwidthofbandisovercomebyusingaflexurallyvibratingdisc,mountedatitscenter,asthetransversemember.Byusingadiscthemassisgreatlyincreasedandthereforeamuchnarrowerbandmaybeobtained.Asinglediscwillprovideapeakofattenuationeitheraboveorbelowtheband.Twodiscslocatednearthemid-pointofthecentralrodandclosetogetherwillprovideapeakaboveandapeakbelowtheband.Thecentralrodhasasmallcross-sectionaldimensionscomparedtoitslength,whichisapproximatelyequaltoahalfwave-lengthatafrequencywithintheband.Thenatureoftheinventionwillbemorefullyunderstoodfromthefollowingdetaileddescriptionandbyreferencetotheaccompanyingdrawing,inwhichlikereferencecharactersrefertosimilarpartsandinwhich:Fig.1isaperspectiveviewofamechanicalwavefilterinaccordancewiththeinventionemployingasingledisc,andFig.2isaperspectiveviewofatwo-discfilter.Takingupthefiguresinmoredetail,Fig.1showsamechanicalwavefilterinaccordancewiththeinventioncomprisingacentralrod1ofcircularcrosssectionandatransversedisc2，bothmadeofsuitableacousticmaterial.ThediameterAoftherod1issmallcomparedtoitslengthB,whichisapproximatelyahalfwave-lengthatacut-offfrequency.Thedisc2hasadiameterCandthicknessDandiscentrallymountednearthecenteroftherod1.Longitudinalvibrationsimpresseduponanendofthebar1byasuitabledrivingdevice,representeddiagrammaticallybythebox3showninbrokenoutline,willcausethedisc2tovibrateintheflexuralmode.Thelongitudinalvibrationsoftherod1maybepickedupattheotherendofthefilterbysomesuitabledevice,representedbythebox4showninbrokenoutline.Apeakofattenuationwilloccurateachfrequencyatwhichthedisc2isantiresonant.ThedimensionsCandDofthedisc2are,therefore,soproportionedthatthefirstflexuralantiresonancefl,givenapproximatelybythefollowingformula,occursatafrequency,usuallynearabandlimit,atwhichapeakisdesired:(1)whereCandDareincentimeters,Misthedensityofthematerial,PisPoisson'sratioandYisYoung'smodulus.Ifflisonthelowersideofthetransmissionband,thelengthBoftherod1ismadeapproximatelyequaltoahalfwavelengthattheuppercut-offfrequency.Ifflisabovetheband,Bismadeapproximatelyequaltoahalfwave-lengthatthelowercut-off.Iftwopeaksofattenuationaredesired,oneoneithersideofthebandandclosetothebandlimits,thestructureshowninFig.2maybeused.Thefiltercomprisesacentralrod1andtwotransverse,centrallymounteddiscs5and6,locatedclosetogetheroneoneithersideofthecenteroftherod1.Oneofthediscshasitsfirstflexuralantiresonanceatafrequencyclosetoonelimitofthebandandtheotherdischasitsfirstflexuralantiresonanceclosetotheotherlimitoftheband.InthiscasethelengthBoftherod1isapproximatelyequaltoahalfwavelengthatthe-bandfrequency.InmechanicalfiltersofthetypeshowninFigs.1and2,employingtransverseimpedancemembers,foragivenrod1thewidthofthebanddecreaseswithanincreaseinthemassofthetransversemembers.Theuseofdiscs,suchas2,5and6,forthesemembersallowstheirmasstobegreatlyincreasedascompared,forexample,withcrossbars,andthereforeamuchnarrowerbandmaybeobtained.Theformerlimitontheminimumbandwidthobtainablewithfiltersusingtransversemembersisthusgreatlyloweredinthedisc-typefiltersofthepresentinvention.Anotherdistinctadvantageofthedisc-typefilterisitsmechanicalsimplicity.Thefiltermay,forexample,bemadefromasinglepieceofmetalandcheaplyturnedoutonalathe.TheimageimpedanceZofthefilter,whichshouldmatchtheimageimpedanceofthedrivingmeansatthemid-bandfrequency,isgivenbytheformula:(2)wherewistheangularfrequency,jisthequadrantaloperator,Visthevelocityofpropagation,equaltothesquarerootoftheratioofYtoM,Z0isthecharacteristicimpedanceoftherod1andZDistheimpedanceofthedisc2,forthefilterofFig.1,orthesumoftheimpedancesofthetwodiscs5and6,forthefilterofFig.2.Thisimageimpedanceisofatypewhichcanbereadilymatchedbyadrivercomprisingapiezoelectriccrystalattachedatitsendtoanendoftherod1.Thefilterwillhaveatransmissionbandbelow,andoneormorebandsabove,theprincipalbandwhichhasbeenhereconsidered.Theseextraneousbands,ifobjectionable,maybeeliminatedbyattenuationprovidedbythedrivingmeans,whichshouldbedesignedtohaveatransmissionbandcoinciding，withtheprincipalbandofthemechanicalfilter.Thediscriminationofthefiltermay,ofcourse,beincreaseddyconnectingintandemtwoormoresectionsofthetypeshowninFig.1orFig.2.Whatisclaimedis:1.Amechanicalwavefilterfortransmittingabandoffrequenciescomprisingarodandatransversediscbothmadeofacousticmaterial,saidrodhavingalengthapproximatelyequaltoahalfwave-lengthatafrequencywithinsaidbandandsaiddiscbeingcentrallymountednearthecenterofsaidrodandadaptedtobesetintoflexuralvibrationbylongitudinalvibrationsimpresseduponanendofsaidrodandhavingaflexuralantiresonanceatafrequencyclosetoonelimitofsaidband.2.Afilterinaccordancewithclaim1inwhichsaidrodhasacircularcrosssection.3.Afilterinaccordancewithclaim1inwhichthecross-sectionaldimensionsofsaidrodaresmallcomparedtoitslength.4.Afilterinaccordancewithclaim1inwhichsaidrodhasacircular,crosssectionthediameterofwhichissmallcomparedtoitslength.5.Afilterinaccordancewithclaim1inwhichsaidflexuralantiresonanceofsaiddiscisitsfirst.6.Amechanicalwavefilterfortransmittingabandoffrequenciescomprisingarodandatransversediscbothmadeofacousticmaterial,saidrodhavingalengthapproximatelyequaltoahalfwave-lengthatafrequencywithinsaidbandandsaiddiscbeingcentrallymountednearthecenterofsaidrodandadaptedtobesetintoflexuralvibrationbylongitudinalvibrationsimpresseduponanendofsaidrodandhavingitsfirstflexuralantiresonanceatafrequencyononesideofsaidbandandsaidrodhavingalengthapproximatelyequaltoahalfwave-lengthatthebandlimitontheothersideofsaidband.7.Afilterinaccordancewithclaim1inwhichsaidflexuralantiresonanceofsaiddiscisitsfirstandsaidrodhasalengthapproximatelyequaltoahalfwave-lengthattheotherlimitofsaidband.8.Amechanicalwavefilterfortransmittingabandoffrequenciescomprisingarodandatransversediscbothmadeofacousticmaterial,saidrodhavingalengthapproximatelyequaltoahalfwave-lengthatafrequencywithinsaidbandandsaiddiscbeingcentrallymountednearthecenterofsaidrodandadaptedtobesetintoflexuralvibrationbylongitudinalvibrationsimpresseduponanendofsaidrodandhavingitsfirstflexuralantiresonanceatafrequencyontheuppersideofsaidbandandsaidrodhavingalengthapproximatelyequaltoahalfwave-lengthatthelowerlimitofsaidband.9.Afilterinaccordancewithclaim1inwhichsaidflexuralantiresonanceofsaiddiscisitsfirstandislocatedabovesaidbandandsaidrodhasalengthapproximatelyequaltoahalfwave-lengthatthelowerlimitofsaidband.10.Amechanicalwavefilterfortransmittingabandoffrequenciescomprisingarodandatransversediscbothmadeofacousticmaterial,saidrodhavingalengthapproximatelyequaltoahalfwave-lengthatafrequencywithinsaidbandandsaiddiscbeingcentrallymountednearthecenterofsaidrodandadaptedtobesetintoflexuralvibrationbylongitudinalvibrationsimpresseduponanendofsaidrodandhavingitsfirstflexuralantiresonanceatafrequencyonthelowersideofsaidbandandsaidrodhavingalengthapproximatelyequaltoahalfwave-lengthattheupperlimitofsaidband.11.Afilterinaccordancewithclaim1inwhichsaidflexuralantiresonanceofsaiddiscisitsfirstandislocatedbelowsaidbandandsaidrodhasalengthapproximatelyequaltoahalfwave-lengthattheupperlimitofsaidband.12.Amechanicalwavefilterfortransmittingabandoffrequenciescomprisingarodandtwotransversediscs,saidrodhavingalengthapproximatelyequaltoahalfwave-lengthatafrequencywithinsaidband,saiddiscsbeingcentrallymounted,locatedclosetogethernearthecenterofsaidrodandadaptedtobesetintoflexuralvibrationbylongitudinalvibrationsimpresseduponanendofsaidrod,oneofsaiddiscshavingaflexuralantiresonanceatafrequencybelowsaidbandandtheotherofsaiddiscshavingaflexuralantiresonanceatafrequencyabovesaidband.13.Afilterinaccordancewithclaim12inwhichsaiddiscsarelocatedoneoneithersideofthecenterofsaidrod.14.Afilterinaccordancewithclaim12inwhichsaidrodhasalengthapproximatelyequaltoahalfwave-lengthatthemid-bandfrequency.15.Afilterinaccordancewithclaim12inwhichsaidflexuralantiresonancesarelocated,respectively,closetothelimitsofsaidband.16.Afilterinaccordancewithclaim12inwhichsaidflexuralantiresonanceofsaidonediscistheonlyoneoccurringbelowsaidbandandsaidflexuralantiresonanceofsaidotherdiscisitsfirst.17.Amechanicalwavefilterfortransmittingabandoffrequenciescomprisingarodandtwotransversediscs,saidrodhavingalengthapproximatelyequaltoahalfwave-lengthatafrequencywithinsaidband,saiddiscsbeingcentrallymounted,locatedclosetogethernearthecenterofsaidrodandadaptedtobesetintoflexuralvibrationbylongitudinalvibrationsimpresseduponanendofsaidrod,oneofsaiddiscshavingitsfirstflexuralantiresonanceatafrequencyclosetoonelimitofsaidbandandtheotherofsaiddiscshavingitsfirstflexuralantiresonanceatafrequencyclosetotheotherlimitofsaidband.18.Afilterinaccordancewithclaim17inwhichsaidrodhasalengthapproximatelyequaltoahalfwave-lengthatthemid-bandfrequency.WARRENP.MASON.翻译Thisinventionrelatestomechanicalwavefiltersandmoreparticularlytothosewhichcompriseoneormoretransversemembersadaptedforflexuralvibration.本发明涉及机械滤波器，特别是那些包含一个或多个适应弯曲振动的横向构件。Anobjectoftheinventionistoreducetheminimumwidthoftransmissionbandobtainableinamechanicalwavefilterwhichemploysatransverseflexuralvibratorymember.该发明的目的是要减少在机械滤波器能得到的传输频带的最小宽度，它采用了横向弯曲振动的构件。Otherobjectsoftheinventionaretosimplifythemechanicalstructureandreducethecostoffiltersofthistype.该发明的其他目的是简化机械结构和降低这种类型过滤器的成本。Oneformofmechanicalwavefiltercomprisesacentralrodofacousticmaterialandoneormorecentrallylocatedtransversemembersadaptedtobesetintoflexuralvibrationwhenlongitudinalvibrationsareimpresseduponanendoftherod.机械滤波器的一种形式由吸音材料的中央杆和一个或多个中心放置的横向构件组成，当纵向振动在杆的末端留下印记，它就相应地被设置成弯曲振动。Foragivenrod,thewidthofthetransmissionbanddecreasesasthemassofthetransversemembersisincreased.对于一个给定杆，传输频带宽度减小，而横向构件的数量增加。衰减峰出现在横向构件的反共振频率，这些峰通常位于接近频带的限度，来获得大幅度削减。Heretofore,thetransversemembershavebeenmadeintheformofcrossbars.迄今为止，横向构件一直被制成横杆的形式。杆的弯曲反共振与其宽度成正比，与其长度的平方成反比。由于反共振频率是固定的，以提高质量，从而缩窄频带，杆的宽度可以通过一个系数K增加，其长度同时通过K的平方根增加。然而，这一点达到时长宽比是如此大，以致于杆将不再以弯曲模式平稳振动。因此，使用横杆过滤器获得的最低频带宽度有相当明确的限制。Inaccordancewiththepresentinventionthislimitationonminimumwidthofbandisovercomebyusingaflexurallyvibratingdisc,mountedatitscenter,asthetransversemember.与现在的发明相一致，频带的最小宽度限制通过使用安装在中心、作为横向构件的弯曲振动圆盘克服。通过使用圆盘，质量大大提高，并因此可能获得一个更窄的波段。一个单独圆盘，将提供高于或低于频带的衰减峰。位于靠近中央棒的中点和并拢的两盘将提供高于和低于频带的衰减峰。与其长度相比，中央棒有一个小的横截面，约等于这是频率带内的半波长度。Thenatureoftheinventionwillbemorefullyunderstoodfromthefollowingdetaileddescriptionandbyreferencetotheaccompanyingdrawing,inwhichlikereferencecharactersrefertosimilarpartsandinwhich:本发明的本质，将从下面的详细描述，和参考所附图纸中得到更充分的了解，参考特性是指像类似的零件和：Fig.图1是一个机械滤波器的透视图，与使用单圆盘的发明一致。Fig.图22isaperspectiveviewofatwo-discfilter.是两盘式过滤器的透视图。Takingupthefiguresinmoredetail,Fig.图中更多的细节：图1显示了一个机械滤波器，与发明一致，由一个圆截面部分的中央杆1和横向盘2组成，均由合适的隔音材料制成。杆1的直径A与它的长度B相比是小的，大约是截止频率处波长的一半。圆盘2有一个直径C和厚度D，并集中安装杆1的中心附近。通过合适的驱动装置在杆1的末端留下印记的纵向振动，通过方框3破碎的轮廓中以图表形式表示，将导致圆盘2以弯曲模式振动。杆1的纵向振动可以在过滤器的另一端通过一些合适的设备拾取，在显示框4中以破碎轮廓表示。Apeakofattenuationwilloccurateachfrequencyatwhichthedisc2isantiresonant.衰减峰将出现在圆盘2反共振频率的任一频率下。因此，圆盘2的圆盘圆盘尺寸C和D如此成比例，以致于第一弯曲反共振fl，约按下列公式计算，发生在通常接近频段限度的频率下，在这需要一个高峰：(1)（1）whereCandDareincentimeters,Misthedensityofthematerial,PisPoisson'sratioandYisYoung'smodulus.其中C和D单位是厘米，M是材料的密度，P为泊松比，Y是杨氏模量。如果fl在传输频带的下侧，杆1的长度B约等于。如果fl在频段以上，B约等于下截止频率的半波长。Iftwopeaksofattenuationaredesired,oneoneithersideofthebandandclosetothebandlimits,thestructureshowninFig.如果想要衰减的两峰，一个在频带任一侧，一个接近频带限度，可以使用图2所示结构。Thefiltercomprisesacentralrod1andtwotransverse,centrallymounteddiscs5and6,locatedclosetogetheroneoneithersideofthecenteroftherod1.该过滤器包括一个中央杆1和集中安装在圆盘5和6的两个横件，紧密位于杆1中心的两侧之一。一个圆一个一个一个一个盘在频率接近频段限度处有第一弯曲反共振频率，另一个圆盘有接近频段另一限度的弯曲反共振频率。在这种情况下，杆1的长度B约等于一个波段频率的半波长。InmechanicalfiltersofthetypeshowninFigs.图1和2所示类型的机械滤波器器，采用横向的阻抗构件，对于一个给定的杆1，频带宽度随横向构件数量的增加而增加。诸如2，5和6这些构件，圆盘的使用允许其数量将大大增加，例如，通过横杆可因此获得一个更窄的波段。使用横向构件过滤器拾取的最低频带宽度，从而在本发明的碟型过滤器中大大降低。碟型过滤器的另一个显著优点是它的机械结构简单。例如，过滤器可以用单一的金属片廉价地用到车床上。TheimageimpedanceZofthefilter,whichshouldmatchtheimageimpedanceofthedrivingmeansatthemid-bandfrequency,isgivenbytheformula:滤波器的图像阻抗Z，应该匹配在中波段频率驱动方式的图像阻抗，以下列公式给出：(2)（2）wherewistheangularfrequency,jisthequadrantaloperator,Visthevelocityofpropagation,equaltothesquarerootoftheratioofYtoM,Z0isthecharacteristicimpedanceoftherod1andZDistheimpedanceofthedisc2,forthefilterofFig.1,orthesumoftheimpedancesofthetwodiscs5and6,forthefilterofFig.其中w是角频率，j为象限算符，V为传播速度，等于Y与M比值的平方根，Z0是杆1的特性阻抗，ZD是图1过滤器圆盘2的阻抗，，或图2过滤器两盘5和6的阻抗的总和。图像