逻辑门混频器的特性分析与选择

:1004-9037(2011)01-0063-06张伟玉1,2　董晋峰2　张国雄1　单慧勇2(1.,,300072;2.,,300384):在基于频率输出的传感器测量电路设计中,存在如何测量由测量参数引起的小频率增量问题,将被测信号和参考信号进行混频并进行滤波可以解决这个问题。将仅频率变化的两准数字信号施加于逻辑门进行混频,对混频器输出的特性进行了理论分析和实验验证,结果表明:异或门和同或门用作差频测量的混频器时,其输出效果明显好于其他基本逻辑门;当信号为占空比50%的方波时,异或门和同或门的输出中不含输入信号的频率,滤波电路相对简单。:逻辑电路;混频器;微差测量法;频率测量:TN911.72:A:(20070913):2009-07-26;:2010-04-12ChoosingSuitableLogicGateMixerforMeasuringFrequencyDifferenceZhangWeiyu1,2,DongJinfeng2,ZhangGuoxiong1,ShanHuiyong2(1.StateKeyLaboratoryofPrecisionMeasuringTechnologyandInstruments,TianjinUniversity,Tianjin,300072,China;2.DepartmentofElectromechanicalEngineering,TianjinAgricultureUniversity,Tianjin,300384,China)Abstract:Inthedesignofmeasuringcircuitsbasedonfrequencytransducers,itisnecessarytomeasuresmallfrequencyincrementscausedbythechangeofthemeasuredparameter.Themixerreceivesinputsfromthereferenceoscillatorandthemonitoroscillator,andalowpassfilterproducesanoutputwiththedifferenceofthetwoinputfrequencies.Twoquasi-digitalsignalsareconnectedtotheinputsofthelogicgatemixersandtheoutputcharacteristicsofthemixersarestudiedintheoriesandexperiments.ResultsshowthatXORandXNORlogicgatemixershavebetterperformancesformeasuringdifferencefrequencythanotherlogicgatemix-ers.Thedutycycleofinputsignalshasaninfluenceontheoutputperformanceofmixersandthereisasimplelow-passfiltercircuitat50%dutycycle.Keywords:logiccircuit;mixers;differentialmeasurementmethod;frequencymeasurement,Parosci-entific,,38kHz42kHz,38kHz,4kHz;0C+125C,170kHz171kHz,170kHz,6kHz,,0.025%,,,;,,,,,,,26120111JournalofDataAcquisition&ProcessingVol.26No.1Jan.2011,,,f1,f2,,Mf1+Nf2,M,N;f1,f2,,,D[1],,[2-10],D,,D[11],,[12],,,,,,,,,1,,1,1,2,T1,T2,1,2x(t),y(t)F[x(t)]=+n=-11San112(-n1)F[y(t)]=+n=-22San222(-n2):Sa();()x(t),y(t)X()=+n=-n011San112(-n1)Y()=+n=-n022San222(-n2)C1=112,C2=222,F[x(t)]=2C1()+X()F[y(t)]=2C2()+Y()X()*Y()=+m=-m0+n=-n011Sam11222San222(-m1-n2)X()*Y(),x(t),y(t)50%,C1=C2=0.5,X()*Y()=2+m=-m0+n=-n0Sam2San2(-m1-n2)=4+m=-+n=-(-1)m+n[-(2m+1)1-(2n+1)2](2m+1)(2n+1),X()*Y()x(t),y(t)1.1x(t),y(t)F[x(t)y(t)]=12[2C1()+X()]*[2C2()+Y()]=2C1C2()+C1Y()+C2X()+12X()*Y()50%F[x(t)y(t)]=2()+12Y()+12X()+12X()*Y()(1)1.2x(t),y(t)F[x(t)y(t)]=F[1-x(t)y(t)]=2()-2C1C2()-C1Y()-C2X()-12X()*Y()50%F[x(t)y(t)]=32()-12Y()-12X()-12X()*Y()(2),,,64261.3x(t),y(t)F[x(t)+y(t)]=F[(1-x(t))(1-y(t))]=2(1-C1-C2+C1C2)()-(1-C2)X()-(1-C1)Y()+12X()*Y()50%,F[x(t)+y(t)]=2()-12X()-12Y()+12X()*Y()(3)1.4x(t),y(t)F[x(t)+y(t)]=F[1-x(t)+y(t)]=2(C1+C2-C1C2)()+(1-C2)X()+(1-C1)Y()-12X()*Y()50%F[x(t)+y(t)]=32()+12X()+12Y()-12X()*Y()(4)(1-4),;X(),Y(),;,180,50%,,,,1.5x(t),y(t)F[x(t)y(t)]=F[x(t)y(t)+x(t)y(t)]=F[1-x(t)y(t)x(t)y(t)]=2()-F[(1-x(t)y(t))(1-x(t)y(t))]=F[x(t)y(t)+x(t)y(t)]=F[x(t)+y(t)-2x(t)y(t)]=2(C1+C2-2C1C2)()+(1-2C2)X()+(1-2C1)Y()-1X()*Y()50%F[x(t)y(t)]=()-1X()*Y()(5)1.6x(t),y(t)F[x(t)y(t)]=F[1-x(t)y(t)]=2(1-C1-C2+2C1C2)()-(1-2C2)X()-(1-2C1)Y()+1X()*Y()50%F[x(t)y(t)]=()+1X()*Y()(6)(5)(6),,180,50%,,,,(1-4),(5-6)X()Y(),50%,();,()x(t),y(t)(),50%,X()(1-2C2)Y()(1-2C1),,50%,,X()*Y(),11Sa11222Sa222(-1+2)+11Sa11222Sa222(+1-2)4sin1T1sin2T2(-1+2)+4sin1T1sin2T2(+1-2)50%,1=T12,2=T22,,;50%,,,,,(),50%2Multisim50%74LS08N74LS86N,651,:,2kHz6kHz1dB20dB,EXCEL2.111010.5kHz1,2,1010.5kHz,,11010.5kHz21010.5kHz2.222.32.4kHz3,4,2.32.4kHz,,,,32.32.4kHz42.32.4kHz3,574LS08N74LS86N,Max2742(6),,GDS-2104,SFG-1013GPC-603005Maxim,R1=237.73k,R2=1.18904MR3=310.125k,R4=1.18407M6Max2743.11010.5kHz55V,f1=10kHz,f2=10.5kHz,66267,8,,,500Hz1010.5kHz,5,,,71010.5kHz81010.5kHz3.22.32.4kHz55V,f1=2.3kHz,f2=2.4kHz,9,10,,9,,,;10,,,100Hz,,92.32.4kHz102.32.4kHz4,;;;50%,50%,,2;50%,,,,;50%,,,,671,:,RC:[1],,.D[J].,2007,28(8):260-263.[2],,,.[J].,2008,21(2):265-268.[3],,,.MEMS[J].,2007,44(7):502-504.[4],,.CMOS[J].,2006,19(5):1863-1870.[5],,,.[J].,2005,26(10):1007-1010.[6],,.[J].,2005,18(1):98-100.[7],,.[J].,2003,26(12):58-60,73.[8],,,.[J].,2000,21(3):270-272,292.[9],,.[J].,1998,17(5):25-28,32.[10]ShivalingappaL,SrinivasanMP,MohanS.Digitalmixerforquartzcrystalthicknessmonitor[J].Vacu-um,1996,47(1):87-89.[11],,.D[J].,2009,22(5):126-127,130.[12],,.[J].,2008,29(6):1260-1264.:(1963-),,,:,E-mail:[e-mail];(1977-),,,:;(1936-),,,,:;(1977-),,,:6826