Third-order active-RC complex filter with automatic frequency tuning for ZigBee transceive
电力系统模块库详解
电力系统模块库电力系统模块库是专用于RLC电路，电力电子电路，电机传动控制和电力系统仿真模块库。
该模块库包含了各种交/直流电源,大量电气元器件和电工测量仪表以及分析工具等。
利用这些模块可以模拟电力系统运行和故障的各种状态,并进行仿真和分析。
电力系统模块库在树状结构窗口名为SimPowerSystems，以SimPowerSystems4。
0为例，展开后如下图所示,共含有7个可用子库和1个废弃的相量子库.SimPowerSystems4.0中还含有一个功能强大的图形用户分析工具Powergui。
1。
Electrical Sources——电源子库 2.Elements——元件子库3.Machines-—电机子库4.Power Electronics—-电力电子子库5。
Measurements--测量子库6。
Phasor Elements——相量子库7。
Application Libraries-—应用子库8.Extra Library——附加子库1。
Electrical Sources-—电源子库电源子库提供了7种电源模块，分别是单相交流电流源，单相交流电压源,单相受控电流源和单相受控电压源，直流电压源，三相可编程电压源和三相电源模块.这些模块的图标及功能简介参见附录表D—1 电源子库模块名用途AC Current Source 提供一个正弦交流电流源AC V oltage Source 提供一个正弦交流电压源Controlled Current Source 提供一个输出电流受输入信号控制的可控电流源Controlled V oltage Source 提供一个输出电压受输入信号控制的可控电压源DC V oltage Source 提供一个直流电压源3—Phase Programmable V oltage Source 提供一个三相可调节电源信号，其中幅值、相角、频率和谐波均可变3-Phase Source 提供一个带有电阻和电感的三相电压源2。
色散线性度可调的大啁啾FBG色散补偿器
色散线性度可调的大啁啾FBG色散补偿器张昊;邱怡申;李晖;陈怀熹;陈书明;吴会松【摘要】Dispersion compensation is a vital factor in optical fiber communication. To the traditional problem of hard-to-control dispersion linearity in large chirped FBG, the relationship between relative chirp coefficient and dispersion linearity is studied. A design of a relay dispersion compensator is demonstrated based on large chirped FBG. The compensator can optimise dispersion linearity via adjusting the ratio of second order chirp coefficient to first order chirp coefficient, with big bandwidth and feasibility of relay dispersion compensation. A numerical simulated experiment of equipping the compensator in a 500 km long, 8 channeles WDM system proves the feasibility of this design.%针对传统大啁啾FBG色散补偿技术中色散曲线线性度难以控制的问题,分析了相对啁啾系数比值与色散线性度之间的关系,依此提出一种基于大啁啾FBG的中继色散补偿器设计方案.该补偿器通过调节一阶和二阶啁啾系数的比值,实现色散曲线线性度可调的功能,且具有补偿带宽范围大、适合WDM系统远程中继补偿的特点.将该设计作为中继补偿器配置在500 km、8通道WDM系统中进行模拟实验,论证了该补偿器的效果.【期刊名称】《桂林理工大学学报》【年(卷),期】2012(032)002【总页数】5页(P276-280)【关键词】大啁啾FBG;色散补偿器;色散线性度;相对啁啾系数【作者】张昊;邱怡申;李晖;陈怀熹;陈书明;吴会松【作者单位】福建师范大学物理与光电信息科技学院,福州350007;福建江夏学院实验与实训中心,福州350007;福建师范大学物理与光电信息科技学院,福州350007;福建师范大学物理与光电信息科技学院,福州350007;福建师范大学物理与光电信息科技学院,福州350007;福建江夏学院实验与实训中心,福州350007;福建江夏学院实验与实训中心,福州350007【正文语种】中文【中图分类】TN929.11色散是光纤通信中不可避免的问题，色散补偿作为通信中的关键技术受到关注。
美军雷达命名规则和雷达英文词汇
美军雷达命名规范按老美军用标准MIL-STD-196D规定，其军用电子设备（包括雷达）根据联合电子类型命名系统（JETDS）。
名称由字母AN（陆军-海军联合命名系统）,一条斜线和另外三个字母组成。
三个字母表示设备安装位置，设备类型和设备用途。
比如AN/SPS-49表示舰载警戒雷达。
数字49标识特定装备，并且表示该设备时JETDS规定的SPS类的第49种。
经过一次修改就在原型后附加一个字母如ABC，名称后加破折号，T和数字表示丫是用来训练的。
名称后的括号内V表示丫是可变系统，就是通过增加或减少设备来完成不同功能的系统。
处于试验和研制中的系统有时在紧随正式名称后的括弧内用特殊标志来表示，他们用来指明研究单位。
比如XB表示海军研究实验室，XW表示罗姆航空发展中心。
下面就把AN/***后面的三个字母的意思祥加说明。
JETDS设备符号安装位置（第一个字母）A 机载B 水下移动式，潜艇D 无人驾驶运载工具F 地面固定G 地面通用K 水陆两用M 地面移动式P 便携式S 水面舰艇T 地面可运输式U 通用V 地面车载W 水面或水下Z 有人和无人驾驶空中运输工具设备类型（第二个字母）A 不可见光，热辐射设备C 载波设备D 放射性检测，指示，计算设备E 激光设备G 电报，电传设备I 内部通信和有线广播J 机电设备K 遥测设备L 电子对抗设备M 气象设备N 空中声测设备P 雷达Q 声纳和水声设备R 无线电设备S 专用设备，磁设备或组合设备T 电话（有线）设备V 目视和可见光设备W 武器特有设备X 传真和电视设备Y 数据处理设备设备用途（第三个字母）A 辅助装置B 轰炸C 通信（发射和接受）D 测向侦查或警戒E 弹射或投掷G 火控或探照灯瞄准H 记录K 计算M 维修或测试工具N 导航（测高，信标，罗盘，测深，进场）Q 专用或兼用R 接收，无源探测S 探测或测距，测向，搜索T 发射W 自动飞行或遥控X 识别Y 监视和火控有源滤波器Active filter有源校正网络Active corrective network 有源干扰Active jamming机载引导雷达 Airborne director radar机载动目标显示 Airborne MTI机载雷达 Airborne radar 机载截击雷达 Airborne-intercept radar 机载警戒雷达 Airborne warning radar模拟信号 Analog signal天线抗干扰技术Antenna anti-jamming technique天线增益 Antenna gain反辐射导弹 Anti-radiation missile背射天线 Backfire antenna回差Backlash 轰炸雷达Bombing radar平衡电感 Balancing inductor选频放大器 Bandpass amplifier战场侦察雷达 Battle-field search radar 盲区 Blind zone闪烁干扰 Blinking jamming击穿功率 Breakdown power体效应二极管本地振荡器Bulk effect diode local oscillator宽带中频放大器 Broad band intermediate frequency amplifier机柜、分机结构 Cabinet, subassembly标定误差 Calibrated error电子束管(阴极射线管) Cathode-ray tube(CRT)空腔型振荡器 Cavity Oscillator谐振腔 Cavity Resonator空腔稳频本地振荡器 Cavity-Stabilized Local Oscillator干扰偶极子 Chaff Dipole信道化接收机 Channelized receiver圆极化平面波Circularly polarized plane wave闭环控制系统（反馈控制系统） Close-loop control system (feed-back control system)杂波抑制 Clutter suppression同轴电缆Coaxial cable 同轴谐振腔Coaxial cavity同轴定向耦合器Coaxial directional coupler 同轴滤波器 Coaxial filter相干振荡器 Coherent oscillator 相干动目标显示 Coherent MTI复调制干扰 Complex modulated jamming圆锥扫描雷达 Conical scan radar圆锥扫描天线 Conical Scanned Antenna连续波雷达接收机 Continuous-wave radar receiver对比度 Contrast 卷积器 Convolutor变频损耗Conversion loss 相关时间Correlation time 抗反辐射导弹措施Counter anti-radiation missile measures正交场器件（M型器件） Crossed-field devices(M-type devices)截止式衰减器 Cut-Off Attenutor截止波长 Cut-off wavelength连续波雷达发射机 CW Radar Transmitter直流阻抗 . impedance直流谐振充电 . resonant charging 直流谐振二极管充电 . resonant diode charge 数据处理 Data processing偏转线圈 Deflection coil延时充电电路 Delayed charging circuit介质移相器 Dielectric phase shifter介质干扰杆 Dielectric chaff rod数字滤波器 Digital filter数字匹配滤波器 Digital matched filter数字测距 Digital ranging引导雷达 Director radar多普勒雷达 Doppler Radar双门限检测器 Double threshold detector 双T接头 Double T-junction等效负载Dummy load 天线收发开关DuplexerE面（H面）折叠双T E plane (H plane) magic-T天线的有效面积 Effective area of an antenna有效辐射功率 Effective radiation power 电液伺服阀Electro-hydraulic Servo value电磁兼容性Electromagnetic compatibility电子抗干扰 Electronic anti-jamming电扫描天线 Electronic Scanned antenna电扫描雷达Electronically Scanned Radar椭圆极化场矢量 Elliptically Polarized Field Vector末制导雷达 End-guidance radar激励器（预调器、触发器）Exciter(premodulator, trigger)极窄脉冲雷达 Extra-short pulse radar快速付里叶变换 Fast Fourier Transform馈电网络 Feed network 相控阵馈电网络Feed networks For Phased Array铁氧体移相器 Ferrite phase shifter火控雷达 Fire control radar 频率捷变雷达 Frequency agile radar调频雷达发射机Frequency modulation radar transmitter引信干扰 Fuse jamming齿轮传动误差 Gear transmission error图形失真校正Graphic distortion correction格雷戈伦天线 Gregarain antenna制导雷达 Guidance radar炮瞄雷达 Gun directing radar 回旋管Gyrotron测高雷达 Height-finding radar水平极化场矢量 Horizontally polarized field vector喇叭天线 Horn antenna 环行电桥 Hybrid ring液压泵 Hydraulic pump阻抗匹配 Impedance match 天线阻抗匹配Impedance match of antenna输入阻抗 Input impedance 天线罩插入相移 Insertion phase of a radome阵列单元的孤立阻抗 Isolated impedance of an array element天线间的隔离Isolation between antennas干扰压制系数 Jamming blanket factor干扰调制样式 Jamming modulation type干扰信号带宽 Jamming signal band width 速调管 Klystron激光雷达 Laser radar 线阵天线 Linear array antenna 负载阻抗 Load impedance低空搜索雷达 Low altitude surveillance radar主振放大式发射机 transmitter磁脉冲调制器 Magnetic pulse modulator 磁控管 Magnetron磁控管灯丝电压控制电路Magnetron filament voltage controlling Circuit主瓣零点宽度Main (major) lobe zero beamwidth 航海雷达 Marine radar 矩阵阵列 Matrix array 气象雷达 Meteorological radar微波带通滤波器Microwave band-pass filter微波场效应晶体管放大器 Microwave field effect transistor amplifier微波全息雷达 Microwave hologram radar 微波低通滤波器Microwave low-pass filter副瓣电平 Minor (side) lobe level机动雷达 Movable radar 阵列天线的互耦Mutual coupling of an array antenna多模馈电器 Multimode feed 多基地雷达Multistatic radar多端网络 Multiport network导航雷达 Navigation radar 噪声调幅干扰 Noise AM jamming噪声调幅调相干扰 Noise AM-PM jamming归一化差斜率Normalized difference slope单通道单脉冲雷达 One-channel Monopulse Radar开环系统频率特性Open-loop system frequency characteristic运算放大器 Operational Amplifier超视距雷达 Over-the-horizon radar过压保护电路Overvoltage protection circuit抛物柱面天线Parabolic cylindrical antenna参量检测器 Parameter detector无源雷达Passive radar相位检波器Phase detector 移相器Phase detector相控阵天线 Phased array antenna 锁相接收机 Phase-locked receiver相位扫描雷达 Phase-scanned radar脉冲压缩雷达 Pulse compression radar 脉冲雷达接收机 Pulse radar receiver相控阵的量化误差 Quantization error of a phased array雷达精度Radar accuracy 雷达反侦察Radar anti-reconnaissance天线罩 Radome采样频率 Sampling frequency 舰载雷达Shipbased radar船用雷达Shipboard radar 侧视雷达Side-looking radar旁瓣对消 Sidelobe Cancellation固体微波振荡器 Solid state microwave oscillator合成孔径雷达 Synthetic radar目标识别雷达Target-identification radar三通道单脉冲雷达接收机 Three-channel monopulse radar receiverT型（Y型）环行器（结环行器） T-type (Y-type) circulator (junction circulator)静电控制超高频电子管（栅控管） UHF electronstatic control tubeV形波束雷达 V-beam radar压控晶体振荡器Voltage controlled oscillator波导谐振腔 Waveguide cavity天气雷达 Weather radar X-Y型天线座X-Y type antenna pedestal八木天线 Yagi antenna雷达覆盖范围 Zone of radar coverage零轴漂移 Zero-axsis drift雷达工作模式：目标捕获系统：The tention action system(该系统配备有嵌入式惯性导航系统和全球定位系统，可在雷达快速展开时提供雷达位置坐标。
一阶低通滤波器不同离散方法结果
一阶低通滤波器不同离散方法结果英文回答：A first-order low-pass filter is a type of analogfilter that allows low-frequency signals to pass through while attenuating high-frequency signals. It is a simple and commonly used filter due to its ease of implementation and low cost.There are two main methods for designing a first-order low-pass filter: the continuous-time (CT) method and the discrete-time (DT) method. The CT method designs the filter in the analog domain, while the DT method designs thefilter in the digital domain.The transfer function of a first-order low-pass filter is given by:H(s) = 1 / (1 + sRC)。
where:s is the complex frequency variable.R is the resistance in the filter.C is the capacitance in the filter.The cutoff frequency of the filter, which is the frequency at which the filter starts to attenuate the signal, is given by:f = 1 / (2πRC)。
NB-IoT芯片RF_Analog前端架构与电路设计要点_EETOP_2017_NB-IoT产业峰会
4-3.RX：DC-offset Cancellation
■ Digital Cancellation ► 先校准，保存SAR
数据，再接收信号 ► NB-IoT推荐使用
·
4-4. RX：ADC
■结构选择 （Why SAR?）：10bits, fs=30.72MHz ► SAR特点：简单（低成本）；
2-4. Low Power Design
■单天线和FDD半双工模式
Release 13 NB-IoT仅支持FDD 半双工模式，意味 着不必同时处理发送和接收，比起全双工成本更低廉， 更省电。
2-5. Low Power Design
■不同工作模式下的功耗比较
耗电：TX > RX > Idle(eDRX) > Sleep(PSM)
3-1. Low-IF RX镜像抑制
■ 复数滤波器（Complex Filter），正负频率 的H(s)不对称，抑制镜像信号
3-2. RX架构的选择
■ NB-IoT zero-IF RX
► 设计要点：
1. DC-offset
cancellation 2. 低频1/f noise的贡献
3-3. DC-offset cancellation
演讲人：杨汝辉
2017.09.20 大唐半导体-射频芯片设计部
ruhuiyang@
目录
• 1. 系统规范 IC SPEC定义？ • 2. 实现Low Power？ • 3. RF收发机（Transceiver）架构? • 4. RX通道Block简介？ • 5. TX通道Block简介？ • 6. Summary
二阶RC有源滤波器的设计!!
湖南人文科技学院毕业设计二阶RC有源滤波器的设计摘要：滤波器是一种能够使有用频率信号通过，而同时抑制（或衰减）无用频率信号的电子电路或装置，在工程上常用它来进行信号处理、数据传送或抑制干扰等。
有源滤波器是由集成运放、R、C 组成，其开环电压增益和输入阻抗都很高，输出阻抗又低，构成有源滤波电路后还具有一定的电压放大和缓冲作用，但因受运算放大器频率限制，这种滤波器主要用于低频范围。
本次毕业设计主要是在所学《模拟电子技术基础》、《集成电路》等专业知识的基础上研究和设计几种典型的二阶有源滤波电路：巴特沃斯二阶有源低通滤波器、巴特沃斯二阶有源高通滤波器、二阶有源带通滤波器，研究和设计其电路结构、传递函数，并对有关参数进行计算，再利用multisim 软件进行仿真，组装和调试各种有源滤波器，探究其幅频特性。
经过仿真和调试，本次设计的二阶RC有源滤波器各测量参数均与理论计算值相符，通频带的频率响应曲线平坦，没有起伏，而在阻频带则逐渐下降为零，衰减率可达到|-40Db/10oct|,滤波效果很理想。
关键词：有源滤波器二阶 RC 频率Abstract：Filter is a kind of can make useful frequency signal through,While suppressing ( or attenuation) useless frequency signal electronic circuit or device, commonly used in engineering to signal processing, data transfer or suppression of interference. Active power filter is composed of integrated operational amplifier, R, C composition, its open loop voltage gain and input impedance is very high, and low output impedance, an active filter circuit also has a voltage amplifying and buffering effect, but due to operational amplifier frequency limit, this filter is mainly used in low frequency range.This graduation design is mainly in the" analog electronic technology"," integrated circuit" and other professional knowledge based on research and design of several typical two order active filter circuit: Butterworth two, Butterworth two step active low pass filter active high-pass filter, two step active band-pass filter, research and design of its circuit structure, transfer function, and the related parameters are calculated, then the use of Multisim software simulation, assembly and commissioning of various active filter, explore its amplitude frequency characteristic.After simulation and debugging, the design of the two order active RC filter the measurement parameters and calculation results, the pass band frequency response curve is flat, no ups and downs, and in the stop band is decreased to zero, attenuation rate can reach | - 40dB / 10oct |, filtering effect is very ideal.Key words: Active power filter Two order RC Frequency Signal第一章前言1.1 选题依据近现代，在电子工程、通信工程、自动控制、遥测控制、测量仪器、仪表和计算机等技术领域，滤波器的应用极为广泛，滤波器的优劣直接决定产品的优劣，所以，对滤波器的研究和生产历来为各国所重视。
【精品】科技英语4低通滤波器原文和翻译
【关键字】精品Words and Expressionsintegrator n. 积分器amplitude n. 幅值slope n 斜率denominator n. 分母impedance n 阻抗inductor n. 电感capacitor n 电容cascade n. 串联passband n 通带ringing n. 振铃damping n. 阻尼，衰减conjugate adj. 共轭的stage v. 成为low-pass filters 低通滤波器building block 模块linear ramp 线性斜坡log/log coordinates 对数/对数坐标Bode plot 伯德图transfer function 传递函数complex-frequency variable 复变量complex frequency plane 复平面real component 实部frequency response 频率响应complex function 复变函数Laplace transform 拉普拉斯变换real part 实部imaginary part 虚部angular frequency 角频率frequency response 频率响应transient response 瞬态响应decaying-exponential response 衰减指数响应step function input 阶跃（函数）输入time constant 时间常数first-order filters 一阶滤波器second-order low-pass filters 二阶低通滤波器passive circuit 无源电路active circuit 有源电路characteristic frequency 特征频率quality factor n. 品质因子，品质因数circular path 圆弧路径complex conjugate pairs 共轭复数对switched-capacitor 开关电容negative-real half of the complex plane 复平面负半平面Unit 4 Low-pass FiltersFirst-Order FiltersAn integrator (Figure 2. la) is the simplest filter mathematically, and it forms the building block for most modern integrated filters. Consider what we know intuitively about an integrator. If you apply a DC signal at the input (i.e., zero frequency), the output will describe a linear ramp that grows in amplitude until limited by the power supplies. Ignoring that limitation, the response of an integrator at zero frequency is infinite, which means that it has a pole at zero frequency. (A pole exists at any frequency for which the transfer function's value becomes infinite.)（为什么为极点，为什么低通？）Figure A simple RC integratorWe also know that the integrator's gain diminishes with increasing frequency and that at high frequencies the output voltage becomes virtually zero. Gain is inversely proportional to frequency, so it has a slope of -1 when plotted on log/log coordinates (i.e., -20dB/decade on a Bode plot, Figure 2. 1b).Figure 2.1 b A Bode plot of a simple integratorYou can easily derive the transfer function asWhere s is the complex-frequency variable and is 1/RC. If we think of s as frequency, this formula confirms the intuitive feeling that gain is inversely proportional to frequency.The next most complex filter is the simple low-pass RC type (Figure 2. 2a). Its characteristic (transfer function) isWhen, the function reduces to , i.e., 1. When s tends to infinity, the function tends to zero, so this is a low-pass filter. When, the denominator is zero and the function's value is infinite, indicating a pole in the complex frequency plane. The magnitude of the transfer function is plotted against s in Figure 2. 2b, where the real component of s () is toward us and the positive imaginary part () is toward the right. The pole at - is evident. Amplitude is shown logarithmically to emphasize the function's form. For both the integrator and the RC low-pass filter, frequency response tends to zero at infinite frequency; that is, there is a zero at. This single zero surrounds the complex plane.But how does the complex function in s relate to the circuit's response to actual frequencies? When analyzing the response of a circuit to AC signals, we use the expression for impedance of an inductor and for that of a capacitor. When analyzing transient response using Laplace transforms, we use sL and 1/sC for the impedance of these elements. The similarity is apparent immediately. The in AC analysis is in fact the imaginary part of s, which, as mentioned earlier, is composed of a real part and an imaginary part.If we replace s by in any equation so far, we have the circuit's response to an angular frequency. In the complex plot in Figure 2.2b, and hence along the positive j axis. Thus, the function's value along this axis is the frequency response of the filter. We have sliced the function along the axis and emphasized the RC low-pass filter's frequency-response curve by adding a heavy line for function values along the positive j axis. The more familiar Bode plot (Figure 2.2c) looks different in form only because the frequency isexpressed logarithmically.（根据图翻译这两句话）Figure 2.2a A simple RC low-pass filterWhile the complex frequency's imaginary part () helps describe a response to AC signals, the real part() helps describe a circuit's transient response. Looking at Figure 2.2b, we can therefore say something about the RC low-pass filter's response as compared to that of the integrator. The low-pass filter's transient response is more stable, because its pole is in the negative-real half of the complex plane. That is, the low-pass filter makes a decaying-exponential response to a step-function input; the integrator makes an infinite response. For the low-pass filter, pole positions further down the axis mean a higher, a shorter time constant, and therefore a quicker transient response. Conversely, a pole closer to the j axis causes a longer transient response.So far, we have related the mathematical transfer functions of some simple circuits to their associated poles and zeroes in the complex-frequency plane . From these functions, we have derived the circuit ’s frequency response (and hence its Bode plot) and also its transient response. Because both the integrator and the RC filter have only one s in the denominator of their transfer functions, they each have only one pole. That is, they are first-order filters .Figure 2.2b The complex function of an RC low-pass filterFigure 2.2c A Bode plot of a low-pass filterHowever, as we can see from Figure 2.1b, the first-order filter does not provide a very selective frequency response. To tailor a filter more closely to our needs , we must move on to higher orders. From now on, we will describe the transfer function using f(s) rather than the cumbersome IN OUT V V . Second-Order Low-Pass FiltersA second-order filter has 2s in the denominator and two poles in the complex plane. You can obtain such a response by using inductance and capacitance in a passive circuit or by creating an active circuit of resistors, capacitors, and amplifiers. Consider the passive LC filter in Figure 2.3a, for instance. We can show that its transfer function has the formand if we defineLC /120=ωand R L Q /0ω=,then where 0ωis the filter's characteristic frequency and Q is the quality factor (lower R means higher Q).Figure 2.3a An RLC low-pass filterThe poles occur at s values for which the denominator becomes zero; that is,when 0/2002=++ωωQ s s . We can solve this equation by remembering that the roots of 02=++c bx ax are given byIn this case, a = 1, b 0ω=, and 20ω=c .The term (ac b 42-) equals ()4/1220-Q ω, so if Q isless than 0.5 then both roots are real and lie on the negative-real axis. The circuit's behavior is much like that of two first order RC filters in cascade . This case isn't very interesting, so we'll consider only the case where Q > 0.5, which means ()ac b 42-is negative and the roots are complex.Figure 2.3b A pole-zero diagram of an RLC low-pass filterThe real part is therefore a b 2/-, which is Q 2/0ω-, and common to both roots. The roots' imaginary parts will be equal and opposite in signs. Calculating the position of the roots in the complex plane, we find that they lie at a distance of0ωfrom the origin, as shown in Figure 2.3b. Varying 0ω, changes the poles' distance from the origin. Decreasing the Q moves the poles toward each other, whereas increasing the Q moves the poles in a semicircle away from each other and toward the ωj axis. When Q = 0.5, the poles meet at 0ω-on the negative-real axis. In this case, the corresponding circuit is equivalent to two cascaded first-order filters.Now let's examine the second-order function's frequency response and see how it varies with Q. As before, Figure 2.4a shows the function as a curved surface, depicted in the three-dimensional space formed by the complex plane and a vertical magnitude vector . Q =0.707, and you can see immediately that the response is a low-pass filter.The effect of increasing the Q is to move the poles in a circular path toward the ωj axis. Figure2.4b shows the case where Q = 2. Because the poles are closer to the ωj axis, they have a greater effect on the frequency response, causing a peak at the high end of the passband .Figure 2.4a The complex function of a second-order low-pass filter (Q = 0.707)Figure 2.4b The complex function of a second-order low-pass filter (Q = 2)There is also an effect on the filter's transient response. Because the poles' negative-real part is smaller, an input step function will cause ringing at the filter output. Lower values of Q result in less ringing, because the damping is greater. On the other hand, if Q becomes infinite, the poles reach the ωj axis, causing an infinite frequency response (instability and continuous oscillation) at 0ωω=. In the LCR circuit in Figure 2.3a, this condition would be impossible unless R=0. For filters that contain amplifiers, however, the condition is possible and must be considered in the design process.A second-order filter provides the variables 0ωand Q, which allow us to place poles wherever we want in the complex plane. These poles must, however, occur as complex conjugate pairs , in which the real parts are equal and the imaginary parts have opposite signs. This flexibility in pole placement is a powerful tool and one that makes the second-order stage a useful component in many switched-capacitor filters. As in the first-order case, the second-order low-pass transfer function tends to zero as frequency tends to infinity. The second-order function decreases twice as fast, however, because of the 2s factor in the denominator. The result is a double zero （零点） at infinity. 低通滤波器一阶滤波器从数学公式上讲，积分器（见图2.1a ）是最简单的滤波器；它是构成大多数现代滤波器的基本模块。
硬件(模电数电电路)术语
硬件术语（电路、模电、数电）电路的基本概念及定律电源source电压源voltage source电流源current source理想电压源ideal voltage source理想电流源ideal current source伏安特性volt-ampere characteristic电动势electromotive force电压voltage电流current电位potential电位差potential difference欧姆Ohm伏特Volt安培Ampere瓦特Watt焦耳Joule电路circuit电路元件circuit element电阻resistance电阻器resistor电感inductance电感器inductor电容capacitance电容器capacitor电路模型circuit model参考方向reference direction参考电位reference potential欧姆定律Ohm’s law基尔霍夫定律Kirchhoff’s law基尔霍夫电压定律Kirchhoff’s voltage law（KVL）基尔霍夫电流定律Kirchhoff’s current law（KCL）结点node支路branch回路loop网孔mesh支路电流法branch current analysis网孔电流法mesh current analysis结点电位法node voltage analysis电源变换source transformations叠加原理superposition theorem网络network无源二端网络passive two-terminal network有源二端网络active two-terminal network戴维宁定理Thevenin’s theorem诺顿定理Norton’s theorem开路（断路）open circuit短路short circuit开路电压open-circuit voltage短路电流short-circuit current交流电路直流电路direct current circuit (dc)交流电路alternating current circuit (ac)正弦交流电路sinusoidal a-c circuit平均值average value有效值effective value均方根值root-mean-squire value (rms)瞬时值instantaneous value电抗reactance感抗inductive reactance容抗capacitive reactance法拉Farad亨利Henry阻抗impedance复数阻抗complex impedance相位phase初相位initial phase相位差phase difference相位领先phase lead相位落后phase lag倒相，反相phase inversion频率frequency角频率angular frequency赫兹Hertz相量phasor相量图phasor diagram有功功率active power无功功率reactive power视在功率apparent power功率因数power factor功率因数补偿power-factor compensation串联谐振series resonance并联谐振parallel resonance谐振频率resonance frequency频率特性frequency characteristic幅频特性amplitude-frequency response characteristic相频特性phase-frequency response characteristic截止频率cutoff frequency品质因数quality factor通频带pass-band带宽bandwidth (BW)滤波器filter一阶滤波器first-order filter二阶滤波器second-order filter低通滤波器low-pass filter高通滤波器high-pass filter带通滤波器band-pass filter带阻滤波器band-stop filter转移函数transfer function波特图Bode diagram傅立叶级数Fourier series三相电路三相电路three-phase circuit三相电源three-phase source对称三相电源symmetrical three-phase source对称三相负载symmetrical three-phase load相电压phase voltage相电流phase current线电压line voltage线电流line current三相三线制three-phase three-wire system三相四线制three-phase four-wire system三相功率three-phase power星形连接star connection(Y-connection)三角形连接triangular connection(- connection ,delta connection) 中线neutral line电路的暂态过程分析暂态transient state稳态steady state暂态过程，暂态响应transient response换路定理low of switch一阶电路first-order circuit三要素法three-factor method时间常数time constant积分电路integrating circuit微分电路differentiating circuit磁路与变压器磁场magnetic field磁通flux磁路magnetic circuit磁感应强度flux density磁通势magnetomotive force磁阻reluctance电动机直流电动机dc motor交流电动机ac motor异步电动机asynchronous motor同步电动机synchronous motor三相异步电动机three-phase asynchronous motor 单相异步电动机single-phase asynchronous motor 旋转磁场rotating magnetic field定子stator转子rotor转差率slip起动电流starting current起动转矩starting torque额定电压rated voltage额定电流rated current额定功率rated power机械特性mechanical characteristic继电器-接触器控制按钮button熔断器fuse开关switch行程开关travel switch继电器relay接触器contactor常开(动合)触点normally open contact常闭(动断)触点normally closed contact时间继电器time relay热继电器thermal overload relay中间继电器intermediate relay可编程控制器（PLC）可编程控制器programmable logic controller语句表statement list梯形图ladder diagram半导体器件本征半导体intrinsic semiconductor掺杂半导体doped semiconductorP型半导体P-type semiconductorN型半导体N--type semiconductor自由电子free electron空穴hole载流子carriersPN结PN junction扩散diffusion漂移drift二极管diode硅二极管silicon diode锗二极管germanium diode阳极anode阴极cathode发光二极管light-emitting diode (LED)光电二极管photodiode稳压二极管Zener diode晶体管（三极管）transistorPNP型晶体管PNP transistorNPN型晶体管NPN transistor发射极emitter集电极collector基极base电流放大系数current amplification coefficient场效应管field-effect transistor (FET)P沟道p-channelN沟道n-channel结型场效应管junction FET（JFET）金属氧化物半导体metal-oxide semiconductor (MOS)耗尽型MOS场效应管depletion mode MOSFET（D-MOSFET）增强型MOS场效应管enhancement mode MOSFET（E-MOSFET）源极source栅极grid漏极drain跨导transconductance夹断电压pinch-off voltage热敏电阻thermistor开路open短路shorted基本放大器放大器amplifier正向偏置forward bias反向偏置backward bias静态工作点quiescent point (Q-point)等效电路equivalent circuit电压放大倍数voltage gain总的电压放大倍数overall voltage gain饱和saturation截止cut-off放大区amplifier region饱和区saturation region截止区cut-off region失真distortion饱和失真saturation distortion截止失真cut-off distortion零点漂移zero drift正反馈positive feedback负反馈negative feedback串联负反馈series negative feedback并联负反馈parallel negative feedback共射极放大器common-emitter amplifier射极跟随器emitter-follower共源极放大器common-source amplifier共漏极放大器common-drain amplifier多级放大器multistage amplifier阻容耦合放大器resistance-capacitance coupled amplifier 直接耦合放大器direct- coupled amplifier输入电阻input resistance输出电阻output resistance负载电阻load resistance动态电阻dynamic resistance负载电流load current旁路电容bypass capacitor耦合电容coupled capacitor直流通路direct current path交流通路alternating current path直流分量direct current component交流分量alternating current component变阻器（电位器）rheostat电阻（器）resistor电阻（值）resistance电容（器）capacitor电容（量）capacitance电感（器，线圈）inductor电感（量），感应系数inductance正弦电压sinusoidal voltage集成运算放大器及应用差动放大器differential amplifier运算放大器operational amplifier(op-amp)失调电压offset voltage失调电流offset current共模信号common-mode signal差模信号different-mode signal共模抑制比common-mode rejection ratio (CMRR) 积分电路integrator（circuit）微分电路differentiator（circuit）有源滤波器active filter低通滤波器low-pass filter高通滤波器high-pass filter带通滤波器band-pass filter带阻滤波器band-stop filter波特沃斯滤波器Butterworth filter切比雪夫滤波器Chebyshev filter贝塞尔滤波器Bessel filter截止频率cut-off frequency上限截止频率upper cut-off frequency下限截止频率lower cut-off frequency中心频率center frequency带宽Bandwidth开环增益open-loop gain闭环增益closed-loop gain共模增益common-mode gain输入阻抗input impedance电压跟随器voltage-follower电压源voltage source电流源current source单位增益带宽unity-gain bandwidth频率响应frequency response频响特性（曲线）response characteristic波特图the Bode plot稳定性stability补偿compensation比较器comparator迟滞比较器hysteresis comparator阶跃输入电压step input voltage仪表放大器instrumentation amplifier隔离放大器isolation amplifier对数放大器log amplifier反对数放大器antilog amplifier反馈通道feedback path反向漏电流reverse leakage current相位phase相移phase shift锁相环phase-locked loop(PLL)锁相环相位监测器PLL phase detector和频sum frequency差频difference frequency波形发生电路振荡器oscillatorRC振荡器RC oscillatorLC振荡器LC oscillator正弦波振荡器sinusoidal oscillator三角波发生器triangular wave generator方波发生器square wave generator幅度magnitude电平level饱和输出电平（电压）saturated output level功率放大器功率放大器power amplifier交越失真cross-over distortion甲类功率放大器class A power amplifier乙类推挽功率放大器class B push-pull power amplifier OTL功率放大器output transformerless power amplifier OCL功率放大器output capacitorless power amplifier直流稳压电源半波整流full-wave rectifier全波整流half-wave rectifier电感滤波器inductor filter电容滤波器capacitor filter串联型稳压电源series (voltage) regulator开关型稳压电源switching (voltage) regulator集成稳压器IC (voltage) regulator晶闸管及可控整流电路晶闸管thyristor单结晶体管unijunction transistor（UJT）可控整流controlled rectifier可控硅silicon-controlled rectifier峰点peak point谷点valley point控制角controlling angle导通角turn-on angle门电路与逻辑代数二进制binary二进制数binary number十进制decimal十六进制hexadecimal二-十进制binary coded decimal （BCD）门电路gate三态门tri-state gate与门AND gate或门OR gate非门NOT gate与非门NAND gate或非门NOR gate异或门exclusive-OR gate反相器inverter布尔代数Boolean algebra真值表truth table卡诺图the Karnaugh map逻辑函数logic function逻辑表达式logic expression组合逻辑电路组合逻辑电路combination logic circuit译码器decoder编码器coder比较器comparator半加器half-adder全加器full-adder七段显示器seven-segment display时序逻辑电路时序逻辑电路sequential logic circuitR-S 触发器R-S flip-flopD触发器D flip-flopJ-K触发器J-K flip-flop主从型触发器master-slave flip-flop置位set复位reset直接置位端direct-set terminal直接复位端direct-reset terminal寄存器register移位寄存器shift register双向移位寄存器bidirectional shift register 计数器counter同步计数器synchronous counter异步计数器asynchronous counter加法计数器adding counter减法计数器subtracting counter定时器timer清除（清0）clear载入load时钟脉冲clock pulse触发脉冲trigger pulse上升沿positive edge下降沿negative edge时序图timing diagram波形图waveform脉冲波形的产生与整形单稳态触发器monostable flip-flop双稳态触发器bistable flip-flop无稳态振荡器astable oscillator晶体crystal555定时器555 timer模拟信号与数字信号的相互转换模拟信号analog signal数字信号digital signalAD转换器analog -digital converter (ADC)DA转换器digital-analog converter (DAC)半导体存储器只读存储器read-only memory（ROM）随机存取存储器random-access memory（RAM）可编程ROM programmable ROM（PROM）。