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1、毕业设计(论文)数字调频信号发生器的系统设计系别专业班级姓名指导教师摘要信号发牛器是一类非常重要的电子仪器,在做实验、进行产品研制和调试以及系统测试中都是必不可少的,而传统的信号发生器性能是非常有限的,满足不了有些用户的要求。直接数字式频率合成技术DDS(DirectDigitalSynthesis)是新一代的频率合成技术,它采用数字控制信号的相位增量技术,具有频率分辨率高,频率切换快,频率切换时相位连续和相位噪声低以及全数字化易于集成等优点而被广泛采用。近儿年超高速数字电路的发展以及对DDS的深入研究,DDS的最高工作频率以及噪声性能己接近并达到锁相频率合成器相
2、当的水平。随着这种频率合成技术的发展,现已广泛应用于通讯、导航、雷达、遥控遥测、电子对抗以及现代化的仪器仪表工业等领域。本文在分析现有信号发生器的工作原理基础上,根据系统指标合理地采用了DDS技术,以AD9854芯片为核心,以Atmel公司的单片机芯片AT89S52为主控机,设计了一种结构简单性能优良的信号发生器。该信号发生器具有输出频率准确、频率稳定度高、频率分辨率高频率转换速度快、产生调制信号、杂散抑制良好等特点。关键词:DDS技术信号发牛器AD9854AT89S52AbstractSignalgeneratorisveryimportantinmoderne
3、lectronicinstruments.Intheexperiments,productdevelopmentanddebuggingandsystemtestingisessential,andthetraditionalsignalgeneratorperformanceisverylimited,cannotmeettherequirementsofsomeusers.DirectDigitalSynthesisisthenewgenerationoffrequencysynthesistechnology,itusesthenumericalcontro
4、lsignalthephaseincreasetechnology,hasthefrequencyresolutionhigh,thefrequencycutsquickly,whenfrequencycutthephasecontinuouslylowaswellastheentiredigitizationiseasywiththephasenoisetointegrateandsoonthemeritiswidelyused.Inrecentyearsthesupervelocitydigitalcircuitdevelopmentaswellastothe
5、DDSthoroughresearch,theDDShighestoperatingfrequencyaswellasthenoiseperformanceapproachedandachievesthephase-lockfrequencysynthesizersuitablelevel.Alongwiththiskindoffrequencysynthesistechnologydevelopment,alreadywidelyappliedtothecommunication,thenavigation,theradar,remotecontroltelem
6、etering,electroniccountermeasureaswellasmodernizeddomainandsooninstrumentmeasuringapplianceindustry.Thisarticleintheanalysisexistingsignalgeneratingdeviceprincipleofworkfoundation,reasonablyhasusedtheDDStechnologyaccordingtothesystemtarget,taketheAD9854chipasthecore,byAtmelCorporation
7、'smonolithicintegratedcircuitchipAT89S52primarilycontrollingmachine,hasdesignedonekindofstructuresimpleperformancefinesignalgeneratingdevice.Thissignalgeneratingdevicehastheoutputfrequencyaccurately,thefrequencystabilityhigh,thefrequencyresolutionhigh-frequencyconversionratequick,prod
8、ucest