1分类号编号毕业论文题目:小功率语音调频发射电路设计学院:电子信息与电气工程学院姓名:缑云飞专业:电子信息科学与技术学号:研究类型:应用研究指导教师:刘秉科提交日期:2016年4月28日[键入文字]1原创性声明本人郑重声明:本人所呈交的论文是在指导教师的指导下独立进行研究所取得的成果。学位论文中凡是引用他人已经发表或未经发表的成果、数据、观点等均已明确注明出处。除文中已经注明引用的内容外,不包含任何其他个人或集体已经发表或撰写过的科研成果。本声明的法律责任由本人承担。论文作者签名:年月日论文指导教师签名:[键入文字]2小功率语音调频发射电路设计缑云飞(电子信息与电气工程学院电子信息科学与技术,甘肃,天水,741000)摘要调频发射器是无线通信传输业务的主要方式,利用它可以使音频信息传送到附近的任意一个FM接收机,并能实现良好的语音传输效果。本文在研究调频发射与接收原理的基础上,进一步分析了调频发射的实用电路,采用QN8027调频发射集成电路来产生调频发射信号,并结合单片机控制技术,设计了发射频率可设定、驻极体话筒放大、负压发生电路等模块,实现了发射频率在88MHz—98MHz可调,传输距离为20米的语音调频发射电路。该电路可实现无明显失真的语音信号传输。关键词:调频发射,单片机控制,QN8027,语音放大,无明显失真[键入文字]3AsmallvoicefrequencymodulationlaunchpowercircuitdesignYunfeiGou(Electronicinformationandelectricalengineeringcollege,TianshuiNormalUniversity,tianshui,gansu,741000)AbstructFMtransmitteristhemainmodeofwirelesscommunicationtransmissionbusiness,itcanbeusedtomaketheaudioinformationtransmittedtoanynearbyFMreceiver,andcanachievegoodvoicetransmissioneffect.Basedonthestudyoftheemittingandreceivingfrequencymodulationprinciple,onthebasisoffurtheranalysisofthefrequencymodulationofpracticalcircuit,usingQN8027liftofffromitslaunchintegratedcircuittogeneratetheFMfrequencymodulationsignal,andcombinedwithsingle-chipcomputercontroltechnology,thedesignofthetransmittingfrequencycanbeset,electretmicrophoneamplifier,negativepressuresuchascircuitmodule,realizesthetransmissionfrequencyat88MHz—98MHzisadjustable,thetransmissiondistanceof20metersvoicefrequencymodulationlaunchcircuit.Noobviousdistortionofthiscircuitcanrealizevoicesignaltransmission.Keywords:Frequencymodulatedtransmission,MCUcontrol,QN8027,Voiceamplification,Noobviousdistortion[键入文字]4目录1.概述.............................................................................................................................11.1调频通信现状..........................................................................................................11.2课题研究目的及意义..............................................................................................11.3课题主要研究内容..................................................................................................12.语音调频发射电路整体设计.....................................................................................22.1整体电路系统框图..................................................................................................22.2设计要求..................................................................................................................33.硬件电路设计.............................................................................................................33.1.单片机控制电路设计..............................................................................................33.1.1.STC89C52RC单片机介绍.................................................................................33.1.2.应用电路设计.......................................................................................................53.2.调频发射电路设计..................................................................................................63.2.1.QN8027调频发射芯片介...................................................................................63.2.2.调频发射模块应用设计.......................................................................................63.3.人机交互电路设计..................................................................................................73.3.1.1602液晶屏显示电路设计.................................................................................73.3.2.应用电路设计.....................................................................................................93.4.24C02存储电路设计.............................................................................................93.5.语音放大滤波电路设计........................................................................................103.6.电源及负压发生电路设计....................................................................................123.6.1.电源电路设计...................................................................................................123.6.2.负压发生电路设计...........................................................................................124.控制软件设计...........................................................................................................135.电路测试与分析论证...............................................................................................146.全文总结...................................................................................................................15致谢..........................................................................................................................16参考文献......................................................................................................................17附录硬件原理图........................................................................................................18[键入文字]11.概述1.1调频通信现状人类社会进入信息时代后,通信成为维持社会发展的基础力量,在人们广泛使用的无线广播通信中,调制方式由二十世纪二三十年代的幅度调制发展到八九十年代的频率调制,克服了中波广播串台严重、信噪比差和频带分配不足的问题,调频广播具有动态范围宽、高保真度、较少串台、信噪比好、抗干扰能力强等优点,在已成为城市广播的主要方式,发射功率也由100W、300W上升到1KW、3KW,实现了全面的覆盖和用户良好的接收效果。在世界各国,频率资源是非常有限的,每个国家都严格限制频率的使用范围,由于传