收发系统射频前端的ADS设计与仿真

ached)andon-timecontrolproblems;severitygreaterrisk,accordingtotherequiredtroubleshooting,registrationform,andsignedbythoseresponsibleforthesecurityoftheunitforthefirstafterescalation.Thirdarticleopenminemanageroncoalmineproductionjobdistrictwithinofsecurityhiddentroubleshooting,andgovernanceandreportfullisresponsiblefor;securityDeputyManagertieManagerwork,theparagraphconstructionteamheadandthebusinessdepartmentheadMember,andrunmaintenancepersonnel,areshouldaccordingtotheirofdutiesrange,onproductionequipment,andfacilities,andsiteenvironment,aspectsofsecurityhiddenforcheckandreport,andbyhiddenrectificationprogrammeforhiddengovernance.Fourthopen-pitminesafetysectionisresponsibleforthesupervisionandinspectionintheproductionareatroubleshooting,managementandreportingofcomprehensivework.Articlescopeandfocusoftheinspectionpersonnelatvariouslevels:1,operatingpersonnelbeforetakingoverandshiftbeforethejurisdictionareatoconductacomprehensiveinspectionofequipment,runningthesquadlea习总书记在梁家河工作生活的那段岁月中，即使条件再艰苦、劳动再繁忙、书籍再有限，都废寝忘食的不忘读书，先后阅读了《共产党宣言》《国家与革命》《资本论》等马列经典著作、《中世纪史》《史记选》《中国古代思想是》derondutyduringmajorequipmentoverhaul,beforeandaftertheshifttodesignatedstafftounderstandtheoperationofequipmentintheequipmentandcheckonfocus.2,equipmentrepairequipmenttoselectmaintenancecheckatleasttwiceaweektokeyequipmentanddefectivedevicestoincreasethefrequencyofinspection.Teamleaderdedicatedtothedeviceeverydayoperationofalldeviceswithinthescopeofmaintenancepersonnelunderstandthemaintenanceandinspectionofkeyequipment.Paragraph3,theownerandprofessionalandtechnicalpersonnelshouldbecarriedoutdailyafterworksitevisitinspection...Evening.Controlroom:focusedoncoalseamspontaneouscombustionundertroubleshooting,help,landslide,coalfire,earth-moving,roadcarwallsitesafetysupervision,andconscientiouslyimplementtheminerectificationmeasures.Productiontechnologysection:isresponsiblefortroubleshootingwhetherexistsSupercapacity,andSuper4GHz收发系统射频前端的ADS设计与仿真0引言近年来，随着无线通信业务的迅速发展，通信频段已经越来越拥挤。1985年美国联邦通信委员会(FCC)授权普通用户可以使用902MHz，2．4GHz和5．8GHz三个“工业、科技、医学”(ISM)频段。ISM频段为无线通信设备提供了无需申请在低发射功率下就能直接使用的产品频段，极大地推动了无线通信产业的发展。虽然目前无线数字通信技术已经相当成熟，但射频设计仍然是移动通信设计的瓶颈。射频电路的设计主要围绕着低成本、低功耗、高集成度、高工作频率和轻重量等要求而进行。ISM频段的射频电路的研究对未来无线通信的发展具有重大的意义。国内外许多文献都对此作了研究，文献[2]中介绍了在无线高速数据通信环境下，2．4GHz发射机的设计。文献[3]介绍了一种低功耗的CMOS集成发射机的设计。ADS(AdvancedDesignSystem)软件是Agilent公司在HPEESOF系列EDA软件基础上发展完善的大型综合设计软件。它功能强大能够提供各种射频微波电路的仿真和优化设计广泛应用于通信航天等领域。本文主要介绍了如何使用ADS设计收发系统的射频前端，并在ADS的模拟和数字设计环境下进行一些仿真。1.发射端的建模与仿真由于设计是建立在实验室中已有的中频调制和解调的硬件基础上的，因此发射端和接收端不考虑信号的调制和解调过程。实验室中的中频调制模块可以输出大概8～10dBm的40MHz已调中频信号，经过分析选择，该发射端的各个模块均参考MAXlM公司的集成模块的参数而设计。本地振荡器采用的是MAX2700。MAX2700是压控振荡器，通过设计合适的外围电路可以使它输出2．4GHz的信号。混频器采用的是MAX2660，MAX2660是有源混频器，可以提供一定的增益。功率放大器采用的是MAX2240，MAX2240的最大输出功率是15．3dBm。发射端所用到的滤波器可以使用ADS软件中的滤波器设计工具进行设计。由于实际的滤波器的插入损耗大概为1～2dB，该设计中取滤波器的插入损耗均为1dB。通过在ADS软件中的模拟电路设计环境进行建模。在该发射端模型中，中频信号为40MHz，-10dBm大小的信号。在ADS的模拟设计环境下，对该发射端进行设计并作预算仿真，该仿真主要是为了测量各个模块的增益、噪声系数、三阶互调截点等。该仿真过程如图1所示。ached)andon-timecontrolproblems;severitygreaterrisk,accordingtotherequiredtroubleshooting,registrationform,andsignedbythoseresponsibleforthesecurityoftheunitforthefirstafterescalation.Thirdarticleopenminemanageroncoalmineproductionjobdistrictwithinofsecurityhiddentroubleshooting,andgovernanceandreportfullisresponsiblefor;securityDeputyManagertieManagerwork,theparagraphconstructionteamheadandthebusinessdepartmentheadMember,andrunmaintenancepersonnel,areshouldaccordingtotheirofdutiesrange,onproductionequipment,andfacilities,andsiteenvironment,aspectsofsecurityhiddenforcheckandreport,andbyhiddenrectificationprogrammeforhiddengovernance.Fourthopen-pitminesafetysectionisresponsibleforthesupervisionandinspectionintheproductionareatroubleshooting,managementandreportingofcomprehensivework.Articlescopeandfocusoftheinspectionpersonnelatvariouslevels:1,operatingpersonnelbeforetakingoverandshiftbeforethejurisdictionareatoconductacomprehensiveinspectionofequipment,runningthesquadlea习总书记在梁家河工作生活的那段岁月中，即使条件再艰苦、劳动再繁忙、书籍再有限，都废寝忘食的不忘读书，先后阅读了《共产党宣言》《国家与革命》《资本论》等马列经典著作、《中世纪史》《史记选》《中国古代思想是》derondutyduringmajorequipmentoverhaul,beforeandaftertheshifttodesignatedstafftounderstandtheoperationofequipmentintheequipmentandcheckonfocus.2,equipmentrepairequipmenttoselectmaintenancecheckatleasttwiceaweektokeyequipmentanddefectivedevicestoincreasethefrequencyofinspection.Teamleaderdedicatedtothedeviceeverydayoperationofalldeviceswithinthescopeofmaintenancepersonnelunderstandthemaintenanceandinspectionofkeyequipment.Paragraph3,theownerandprofessionalandtechnicalpersonnelshouldbecarriedoutdailyafterworksitevisitinspection...Evening.Controlroom:focusedoncoalseamspontaneouscombustionundertroubleshooting,help,landslide,coalfire,earth-moving,roadcarwallsitesafetysupervision,andconscientiouslyimplementtheminerectificationmeasures.Productiontechnologysection:isresponsiblefortroubleshootingwhetherexistsSupercapacity,andSuper从表1仿真结果中可以看出，整个发射端的总增益为17．783dB。输入的中频信号为-10dBm，2.接收端的建模与仿真接收端在设计中要考虑增益、噪声系数、灵敏度等因素，比发射端的设计更为复杂。由于接收端包含很多有源器件，有源器件的非线性对整个接收系统会产生很大的影响，比如当只输入一个信号时会出现增益压缩，当输入两个以上的信号时会出现互相调