清华大学电子系前沿课之--电磁波技术

1DepartmentofElectronicsEngineering,TsinghuaUniversity学科前沿课通信和信息系统中的电磁波技术清华大学电子工程系冯正和2005/11/7DepartmentofElectronicsEngineering,TsinghuaUniversity2DepartmentofElectronicsEngineering,TsinghuaUniversity内容一、电磁波技术：频谱资源的有效利用，电波传播特性，天线和天线阵列，新应用系统二、电路技术：微波集成电路，智能化技术，三维集成，RF-MEMS，EBG，超高速电路三、电磁波的新动态和新应用：左手材料、光子晶体，近场技术3DepartmentofElectronicsEngineering,TsinghuaUniversity一、电磁波技术1、频谱资源的开发：2、频谱资源的有效利用：3、电波传播特性4、天线技术5、新应用系统4DepartmentofElectronicsEngineering,TsinghuaUniversity1、频谱资源的开发：新频段的开发，毫米波、红外频率频段应用3Hz~30kHzELF,VLF极,甚低频潜艇通信、导航30~300kHzLF低频远距离导航0.3~3MHzMF中频中波导航、海上通信、调幅广播3~30MHzHF高频短波通信30~300MHzVHF甚高频移动通信、电视、调频广播、雷达0.3~3GHzUHF超高频移动通信、电视、雷达、卫星3~30GHzSHF特高频微波微波通信、雷达、卫星30~300GHzEHF极高频毫米波通信、雷达、卫星300~107GHzIR，远红外，光通信、雷达、卫星5DepartmentofElectronicsEngineering,TsinghuaUniversity2、频谱资源的有效利用：有限的频率资源与急剧增长的需求矛盾。通信技术－提高频谱利用率－bit/Hz/s：提高单位频带的通信速率：模拟→数字，高效调制增加用户数：多址接入，FDMA、TDMA、CDMA信源编码技术：降低码速信道编码：减少干扰和多径引起的误码电波技术：提高频率复用系数：蜂窝、扇区、小区制空间复用技术：智能天线、多天线（MIMO、分布式）电磁兼容技术（空间隔离）6DepartmentofElectronicsEngineering,TsinghuaUniversity二类通信：语音和数据7DepartmentofElectronicsEngineering,TsinghuaUniversity3、电波传播特性大气传播特性，大气吸收电离层：卫星、散射空气折射：平流层、散射（雷达、通信）海洋：用激光雷达测海低石油地面：传播模型，（通信）城市：多径传播模型红外通信：反射模型超宽带通信：传播特性8DepartmentofElectronicsEngineering,TsinghuaUniversity9DepartmentofElectronicsEngineering,TsinghuaUniversity接收天线处空间相关系数0.000.050.100.150.200.250.300.00.20.40.60.81.0空间相关系数T11T12T12T13T13T14接收天线间距（米）IV10DepartmentofElectronicsEngineering,TsinghuaUniversity室内电磁场分布实验™房间高3米™实验台高度81cm™隔墙高度121cm™发射天线：T1，T2，高度1.5米。™接收区域：R1，R2，R3，高度1.5米™接收区域：R4水平位置和R3重合,高度1米™频率：2.075GHz11DepartmentofElectronicsEngineering,TsinghuaUniversity室内电磁场分布12DepartmentofElectronicsEngineering,TsinghuaUniversity4、天线技术宽带/多频段/小型化天线：GSM＋GPS,＋CDMA,＋TV,＋IEEE801,＋Bluetooth•个人通信系统:3G，B3G（2×600MHz带宽）•无线数据通信系统:Bluetooth2.54GHzWLAN:IEEE802.11，2.5,5GHzLMDS:3.5,10,27GHz,UWB：3GHz，10GHz，20GHz，60GHz13DepartmentofElectronicsEngineering,TsinghuaUniversity双频段天线0.51.01.52.02.53.0-20-15-10-50MeasurementSimulationS11(dB)Frequency(GHz)14DepartmentofElectronicsEngineering,TsinghuaUniversity双模天线0.51.01.52.02.53.0-20-15-10-50MeasurementSimulationS11(dB)Frequency(GHz)15DepartmentofElectronicsEngineering,TsinghuaUniversity矩形金属贴片BT形金属贴片yx0.80.91.01.11.21.31.41.51.61.71.81.92.02.12.22.32.42.52.6123456电压驻波比频率(GHz)宽带天线16DepartmentofElectronicsEngineering,TsinghuaUniversityEBG天线减少背向辐射，减少天线间的互耦ProposedStructureSurfaceWavesNoSurfaceWaves17DepartmentofElectronicsEngineering,TsinghuaUniversity小型化EBG结构18DepartmentofElectronicsEngineering,TsinghuaUniversityReducingsubstrateloss：GaAsairsubairPBG19DepartmentofElectronicsEngineering,TsinghuaUniversityMEMSantennas20DepartmentofElectronicsEngineering,TsinghuaUniversityMEMS天线21DepartmentofElectronicsEngineering,TsinghuaUniversity智能天线22DepartmentofElectronicsEngineering,TsinghuaUniversity23DepartmentofElectronicsEngineering,TsinghuaUniversity24DepartmentofElectronicsEngineering,TsinghuaUniversity方向图可调天线25DepartmentofElectronicsEngineering,TsinghuaUniversity26DepartmentofElectronicsEngineering,TsinghuaUniversityMIMO天线27DepartmentofElectronicsEngineering,TsinghuaUniversity多天线终端－四天线28DepartmentofElectronicsEngineering,TsinghuaUniversity1信噪比10db单发单收，2信噪比20db的单发单收3信噪比10db多发多收，4信噪比20db的多发多收多天线系统和单天线系统的信道容量29DepartmentofElectronicsEngineering,TsinghuaUniversity可重构天线Aquasi-YagiV-dipole30DepartmentofElectronicsEngineering,TsinghuaUniversity天线阵列FAST天线馈源超宽带二倍频程高增益30～35dB31DepartmentofElectronicsEngineering,TsinghuaUniversity防撞雷达24GHz/77GHz5、新应用系统32DepartmentofElectronicsEngineering,TsinghuaUniversity33DepartmentofElectronicsEngineering,TsinghuaUniversity34DepartmentofElectronicsEngineering,TsinghuaUniversity超宽带通信:UWB与传统无线系统信号的区别UWB发射信号传统无线发射信号35DepartmentofElectronicsEngineering,TsinghuaUniversity05001000UWB(1000)802.11a(83)Bluetooth(30)802.11a(1)802.11BluetoothUWB谱容量比较容量36DepartmentofElectronicsEngineering,TsinghuaUniversityUWB的应用ƒ区域安全室外贵重物品安全高责任区安全37DepartmentofElectronicsEngineering,TsinghuaUniversity电子标签RFID10MHz,900MHz,2.54GHz,5.8GHzReader38DepartmentofElectronicsEngineering,TsinghuaUniversity39DepartmentofElectronicsEngineering,TsinghuaUniversity40DepartmentofElectronicsEngineering,TsinghuaUniversityPico无线电41DepartmentofElectronicsEngineering,TsinghuaUniversity42DepartmentofElectronicsEngineering,TsinghuaUniversity43DepartmentofElectronicsEngineering,TsinghuaUniversity44DepartmentofElectronicsEngineering,TsinghuaUniversity45DepartmentofElectronicsEngineering,TsinghuaUniversity46DepartmentofElectronicsEngineering,TsinghuaUniversity47DepartmentofElectronicsEngineering,TsinghuaUniversity48DepartmentofElectronicsEngineering,TsinghuaUniversity微波能量传输SpaceSolarPowerSatellitesystem49DepartmentofElectronicsEngineering,TsinghuaUniversity太阳能量卫星（SPS）50DepartmentofElectronicsEngineering,TsinghuaUniversity51DepartmentofElectronicsEngineering,TsinghuaUniversity二、微波及RF集成电路多频段、小型化、智能化、多功能化－－－感知无线电•多频段，宽带化•小型化：混合信号系统，数字和模拟信号混合集成；电磁兼容问题；信号完整性问题，三维电磁场仿真与结构设计；•智能化：电路功能，LNA（宽带、大动态），滤波器（可调），振荡器（多频段、高稳定），功率放大器（线性化、高效）、天线（多频段、智能化）；•多功能化:多频段、多调制方式、多接入方式、多使用方式•目标：感知用户能自己寻找、识别和接入的通信系统。52DepartmentofElectronicsEngin