复旦大学：《集成电路工程》教学资源（硕士士学位论文）功率检测电路设计

学校代码：10246 学号：10210720159 復大學 硕士学位论文 (专业学位) 功率检测电路设计 院 系： 信息科学与工程学院 专 业： 集成电路工程 姓 名： 唐聪 指导教师： 唐长文副教授 完成日期： 2012年4月20日

学校代码： 10246 学 号： 10210720159 硕 士 学 位 论 文 （专业学位） 功率检测电路设计 院 系： 信息科学与工程学院 专 业： 集成电路工程 姓 名： 唐聪 指 导 教 师： 唐长文 副教授 完 成 日 期： 2012 年 4 月 20 日

目录 图目录… …川 表目录… …V川 摘要… …1 Abstract… …3 第一章概述… …5 1.1研究背景及意义 …5 1.2研究现状… 5 1.3论文主要内容和贡献… …6 1.4论文组织结构 …7 第二章数字自动增益控制简介……9 2.1零中频接收机自动增益控制 9 2.1.1自动增益控制基本问题…9 2.1.2零中频接受机自动增益控制方案简介 12 2.2自动增益控制算法实现…13 2.3功率检测电路性能指标 …14 第三章接受信号强度指示电路设计…6 3.1连续检测结构分析…。 6 3.2增益单元及直流消除电路设计…18 3.3整流器及补偿电路设计…27 3.3.1整流器工作原理…27 3.3.2整流器偏差… 29 3.3.3整流器工艺温度特性… 31 3.3.4工艺和温度补偿… 35 3.3.5整流器检测范围及拟合 37 3.4信号特性分析… 39 3.5电路仿真结果… 40 第四章功率检测电路设计… …45 4.1电路结构分析… 45 4.2数字控制放大器设计… 46 4.2.1放大器增益精度… 46 4.2.23dB增益步长… 47 4.2.3频率响应… 49 4.3整流器设计… …51

I 目 录 图目录························································································III 表目录························································································VI 摘 要·························································································1 Abstract······················································································3 第一章 概述················································································5 1.1 研究背景及意义·································································5 1.2 研究现状··········································································5 1.3 论文主要内容和贡献···························································6 1.4 论文组织结构····································································7 第二章 数字自动增益控制简介························································9 2.1 零中频接收机自动增益控制··················································9 2.1.1 自动增益控制基本问题···············································9 2.1.2 零中频接受机自动增益控制方案简介··························· 12 2.2 自动增益控制算法实现······················································ 13 2.3 功率检测电路性能指标······················································ 14 第三章 接受信号强度指示电路设计················································ 16 3.1 连续检测结构分析···························································· 16 3.2 增益单元及直流消除电路设计············································· 18 3.3 整流器及补偿电路设计······················································ 27 3.3.1 整流器工作原理······················································ 27 3.3.2 整流器偏差···························································· 29 3.3.3 整流器工艺温度特性················································ 31 3.3.4 工艺和温度补偿······················································ 35 3.3.5 整流器检测范围及拟合············································· 37 3.4 信号特性分析·································································· 39 3.5 电路仿真结果·································································· 40 第四章 功率检测电路设计···························································· 45 4.1 电路结构分析·································································· 45 4.2 数字控制放大器设计························································· 46 4.2.1 放大器增益精度······················································ 46 4.2.2 3dB 增益步长························································· 47 4.2.3 频率响应······························································· 49 4.3 整流器设计····································································· 51

4.3.1半波整流器工作原理 51 4.3.2误差分析 54 4.3.3频率特性 55 4.4运算求差电路设计及其矫正 55 4.4.1仪表放大器设计 …55 4.4.2失调数字矫正… …56 4.4.3数模转换器设计… 57 4.5信号特性分析… 60 4.6电路仿真结果… 61 第五章总结与展望 67 5.1总结… 67 5.2展望… 67 致谢… 69 参考文献… …71

II 4.3.1 半波整流器工作原理················································ 51 4.3.2 误差分析······························································· 54 4.3.3 频率特性······························································· 55 4.4 运算求差电路设计及其矫正················································ 55 4.4.1 仪表放大器设计······················································ 55 4.4.2 失调数字矫正························································· 56 4.4.3 数模转换器设计······················································ 57 4.5 信号特性分析·································································· 60 4.6 电路仿真结果·································································· 61 第五章 总结与展望····································································· 67 5.1 总结·············································································· 67 5.2 展望·············································································· 67 致谢·························································································· 69 参考文献···················································································· 71

图目录 图1-1低噪声放大器增益控制… …………………5 图1-2连续检测结构框图… …6 图2-1连续检测结构框图… …9 图2-2干扰的两种主要情况 …10 图2-3非线性与噪声特性… 11 图2-4带内信号功率传输特性…12 图2-5功率检测电路传输特性曲线…14 图3-1接受信号强度指示电路框图…16 图3-2限幅器直流传输特性曲线… 17 图3-3信号强度指示电路传输特性曲线 …18 图3-4比例运算放大器 18 图3-5折叠二极管负载放大器…19 图3-6源极退化电阻负载放大器 20 图3-7恒定跨导偏置电路… 21 图3-8典型工艺角仿真结果… 22 图3-9温度扫描仿真结果… 22 图3-10直流消除电路原理…。 ……… 23 图3-11低通滤波器和跨导级… 24 图3-12电平转换电路… 24 图3-13放大器输出失调电压… 25 图3-14放大器输出失调电压（消除后）…25 图3-15放大器幅频频率曲线… 26 图3-16直流消除环路增益… 26 图3-17非平衡源极耦合对全波整流器 …27 图3-18非平衡对直流传输曲线… 28 图3-19整流器直流传输曲线线性近似 28 图3-20整流器直流传输特性… 29 图3-21整流器功率检测特性… 29 图3-22传输特性曲线典型变化… 30 图3-23输出参考直线…30 图3-24非平衡对直流传输特性曲线 31 图3-25比例k对整流器传输曲线影响…32

III 图目录 图 1-1 低噪声放大器增益控制 ··························································5 图 1-2 连续检测结构框图 ································································6 图 2-1 连续检测结构框图 ································································9 图 2-2 干扰的两种主要情况 ··························································· 10 图 2-3 非线性与噪声特性 ······························································ 11 图 2-4 带内信号功率传输特性 ························································ 12 图 2-5 功率检测电路传输特性曲线 ·················································· 14 图 3-1 接受信号强度指示电路框图 ·················································· 16 图 3-2 限幅器直流传输特性曲线 ····················································· 17 图 3-3 信号强度指示电路传输特性曲线 ············································ 18 图 3-4 比例运算放大器 ································································· 18 图 3-5 折叠二极管负载放大器 ························································ 19 图 3-6 源极退化电阻负载放大器 ····················································· 20 图 3-7 恒定跨导偏置电路 ······························································ 21 图 3-8 典型工艺角仿真结果 ··························································· 22 图 3-9 温度扫描仿真结果 ······························································ 22 图 3-10 直流消除电路原理····························································· 23 图 3-11 低通滤波器和跨导级·························································· 24 图 3-12 电平转换电路··································································· 24 图 3-13 放大器输出失调电压·························································· 25 图 3-14 放大器输出失调电压(消除后)··············································· 25 图 3-15 放大器幅频频率曲线·························································· 26 图 3-16 直流消除环路增益····························································· 26 图 3-17 非平衡源极耦合对全波整流器·············································· 27 图 3-18 非平衡对直流传输曲线······················································· 28 图 3-19 整流器直流传输曲线线性近似·············································· 28 图 3-20 整流器直流传输特性·························································· 29 图 3-21 整流器功率检测特性·························································· 29 图 3-22 传输特性曲线典型变化······················································· 30 图 3-23 输出参考直线··································································· 30 图 3-24 非平衡对直流传输特性曲线················································· 31 图 3-25 比例k 对整流器传输曲线影响·············································· 32

图3-26偏置电流产生电路… 33 图3-27偏置电流和转换电阻的影响… 33 图3-28尺寸对传输特性的影响 …34 图3-29亚阈值效应影响… …35 图3-30恒定过驱动电压电路… 36 图3-31电流求差电路… … 37 图3-32整流器曲线拟合… 38 图3-33整流器输出VP曲线… 38 图3-34RSSl输出VP曲线…… 39 图3-35非线性误差特性 41 图3-36RSS引频率特性… 41 图3-37参考功率温度特性曲线 42 图3-38补偿后参考功率温度特性曲线· 42 图3-39输入参考功率分布… 43 图3-40RSS1时间相应曲线… …44 图4-1功率检测电路框图… 45 图4-2电路工作原理示意图 …46 图4-3可编程增益放大器… 46 图4-4放大器增益温度特性 47 图4-5可编程放大器增益步长…49 图4-6共源共栅放大器寄生模型 49 图4-7等效电路图…50 图4-8放大器后仿幅频响应 50 图4-9半波整流器… 51 图4-10半波整流过程 52 图4-11半波整流响应曲线… 53 图4-12PWD实际VP曲线… 53 图4-13过驱动电压差值补偿… 54 图4-14△V温度变化特… …54 图4-15仪表放大器… 56 图4-16电流型数模转换器(6bit)… 58 图4-17DAC微分非线性… 59 图4-18DNL分布情况… 60 图4-19功率检测器VP曲线 … 61 图4-20PD频率特性… 62 图4-21参考功率温度特性曲线… 62 N

IV 图 3-26 偏置电流产生电路····························································· 33 图 3-27 偏置电流和转换电阻的影响················································· 33 图 3-28 尺寸对传输特性的影响······················································· 34 图 3-29 亚阈值效应影响································································ 35 图 3-30 恒定过驱动电压电路·························································· 36 图 3-31 电流求差电路··································································· 37 图 3-32 整流器曲线拟合································································ 38 图 3-33 整流器输出 VP 曲线 ·························································· 38 图 3-34 RSSI 输出 VP 曲线 ··························································· 39 图 3-35 非线性误差特性································································ 41 图 3-36 RSSI 频率特性································································· 41 图 3-37 参考功率温度特性曲线······················································· 42 图 3-38 补偿后参考功率温度特性曲线·············································· 42 图 3-39 输入参考功率分布····························································· 43 图 3-40 RSSI 时间相应曲线··························································· 44 图 4-1 功率检测电路框图 ······························································ 45 图 4-2 电路工作原理示意图 ··························································· 46 图 4-3 可编程增益放大器 ······························································ 46 图 4-4 放大器增益温度特性 ··························································· 47 图 4-5 可编程放大器增益步长 ························································ 49 图 4-6 共源共栅放大器寄生模型 ····················································· 49 图 4-7 等效电路图 ······································································· 50 图 4-8 放大器后仿幅频响应 ··························································· 50 图 4-9 半波整流器 ······································································· 51 图 4-10 半波整流过程··································································· 52 图 4-11 半波整流响应曲线····························································· 53 图 4-12 PWD 实际 VP 曲线 ··························································· 53 图 4-13 过驱动电压差值补偿·························································· 54 图 4-14 V 温度变化特 ································································ 54 图 4-15 仪表放大器······································································ 56 图 4-16 电流型数模转换器(6bit)······················································ 58 图 4-17 DAC 微分非线性······························································ 59 图 4-18 DNL 分布情况·································································· 60 图 4-19 功率检测器 VP 曲线 ·························································· 61 图 4-20 PWD 频率特性································································· 62 图 4-21 参考功率温度特性曲线······················································· 62

图4-22二分法直流失调矫正： 63 图4-23输入参考功率分布…64 图4-24PWD时间响应曲线… 64

V 图 4-22 二分法直流失调矫正·························································· 63 图 4-23 输入参考功率分布····························································· 64 图 4-24 PWD 时间响应曲线··························································· 64

表目录 表3-1放大器幅频响应和输出失调特性…24 表3-2过驱动电压…36 表3-3参考功率工艺角仿真结果…43 表3-4RSSl性能仿真结果…44 表4-1最高增益典型工艺角仿真结果…47 表4-2△V工艺角仿真结果…55 表4-3参考功率工艺角仿真结果…63 表4-4PWD性能总结…65 M

VI 表目录 表 3-1 放大器幅频响应和输出失调特性 ············································ 24 表 3-2 过驱动电压 ······································································· 36 表 3-3 参考功率工艺角仿真结果 ····················································· 43 表 3-4 RSSI 性能仿真结果 ···························································· 44 表 4-1 最高增益典型工艺角仿真结果 ··············································· 47 表 4-2 V 工艺角仿真结果···························································· 55 表 4-3 参考功率工艺角仿真结果 ····················································· 63 表 4-4 PWD 性能总结 ·································································· 65

摘要 现代数字电视调谐器广泛集成自动增益控制模块以扩大调谐器接受信号动 态范围。数字自动增益控制由于不会引入额外噪声，控制算法灵活等优点得到越 来越广泛的研究和应用。 本文主要工作是针对零中频数字调谐器中数字自动增益控制应用要求，设计 了一种低频接受信号强度指示电路和一款射频功率检测电路。 首先，简要介绍了调谐器自动增益控制的基础知识，包括干扰分析和接管点 等，并概述零中频接收机中一种数字自动增益控制方案。同时结合自动增益控制 的应用背景给出功率检测电路的性能参数。 其次，设计了一种低频接受信号强度指示电路。主要回顾连续检测结构的工 作原理，分析电路中放大器和整流器的输出误差，根据理论分析结果设计补偿电 路，并对器件失配做出优化。本次设计得到斜率为38.8 mv/dbm的功率检查曲线， 建立时间小于130us,检测范围为-20dBm~3dBm,频率范围为1KHz~20MHz, 功耗为2mw。 最后，设计一款射频功率检测电路。论文应用了一种单端数字功率检测结构， 主要分析探讨了电路的工作原理，频率特性，检测误差等方面，并且采用二分法 矫正输出直流失调。本次设计结果：频率范围为50M~860M,100us建立时间， 检测范围为-26dBm~-14dBM,功耗3.8mw。 本文所涉及功率检测电路均在TSMC0.18工艺下完成仿真设计。 关键词：数字电视调谐器、数字自动增益控制、接受信号强度指示器、射频功率 检测器、工艺温度补偿、直流失调矫正 中图分类号：TN432 1

1 摘 要 现代数字电视调谐器广泛集成自动增益控制模块以扩大调谐器接受信号动 态范围。数字自动增益控制由于不会引入额外噪声，控制算法灵活等优点得到越 来越广泛的研究和应用。 本文主要工作是针对零中频数字调谐器中数字自动增益控制应用要求，设计 了一种低频接受信号强度指示电路和一款射频功率检测电路。 首先，简要介绍了调谐器自动增益控制的基础知识，包括干扰分析和接管点 等，并概述零中频接收机中一种数字自动增益控制方案。同时结合自动增益控制 的应用背景给出功率检测电路的性能参数。 其次，设计了一种低频接受信号强度指示电路。主要回顾连续检测结构的工 作原理，分析电路中放大器和整流器的输出误差，根据理论分析结果设计补偿电 路，并对器件失配做出优化。本次设计得到斜率为38.8mv/dbm的功率检查曲线， 建立时间小于130us，检测范围为–20dBm~3dBm，频率范围为1KHz~20MHz， 功耗为2mw。 最后，设计一款射频功率检测电路。论文应用了一种单端数字功率检测结构， 主要分析探讨了电路的工作原理，频率特性，检测误差等方面，并且采用二分法 矫正输出直流失调。本次设计结果：频率范围为50M~860M，100us建立时间， 检测范围为–26dBm~–14dBM，功耗3.8mw。 本文所涉及功率检测电路均在TSMC0.18工艺下完成仿真设计。 关键词：数字电视调谐器、数字自动增益控制、接受信号强度指示器、射频功率 检测器、工艺温度补偿、直流失调矫正 中图分类号：TN432

Abstract In order to expand received signal dynamic range,automatic gain control modules are widely integrated in modern digital TV tuners.Because of the advantages of not introducing additional noise and flexible control algorithm, the programmable automatic gain control(PGC)is getting more and more research and application. This mainly work of this dissertation is design a low frequency received signal strength indicator(RSSI)and a radio frequency power detector(PWD), applying to PGC in the tuner with zero IF architecture. First,the basic knowledge of PGC is introduced briefly,including analysis of interference and take-over points,etc,an overview of a PGC scheme applying to zero IF receiver is also introduced.The circuit performance parameters of RSSI and PWD are given in terms of PGC application. Second,the design of RSSI is presented.The principle of successive detection architecture is reviewed;output errors of the amplifier and rectifier are discussed in detail.According to the theoretical analysis,compensation circuits are designed and the performance of device match is also optimized. In this design,the slop of RSSI is 38.8mv/dbm with150us settle time,detection range is-20dbm~3dbm,the effective frequency range can reach 20MHz,the power is 2mw. Finally,the design power detector circuit is introduced.A single ended digital control power detection structure is used.The principle of this architecture,frequency characteristics and detection error is analyzed.The bisection technique is used to calibrate output DC offset.In this work,the frequency band is 50M~860M with-26dBm~-14dBm detection range,the settle time is 100us,the total power is 3.8mw. All the circuits in this work are designed under TSMC0.18 process. Keywords:Digital TV tuner,PGC,RSSI,Power detector,corner and temperature Compensation,DC offset calibration Classification Code:TN432 3

3 Abstract In order to expand received signal dynamic range, automatic gain control modules are widely integrated in modern digital TV tuners. Because of the advantages of not introducing additional noise and flexible control algorithm, the programmable automatic gain control (PGC) is getting more and more research and application. This mainly work of this dissertation is design a low frequency received signal strength indicator (RSSI) and a radio frequency power detector (PWD), applying to PGC in the tuner with zero IF architecture. First, the basic knowledge of PGC is introduced briefly, including analysis of interference and take-over points, etc, an overview of a PGC scheme applying to zero IF receiver is also introduced. The circuit performance parameters of RSSI and PWD are given in terms of PGC application. Second, the design of RSSI is presented. The principle of successive detection architecture is reviewed; output errors of the amplifier and rectifier are discussed in detail. According to the theoretical analysis, compensation circuits are designed and the performance of device match is also optimized. In this design, the slop of RSSI is 38.8mv/dbm with150us settle time, detection range is –20dbm~3dbm, the effective frequency range can reach 20MHz, the power is 2mw. Finally, the design power detector circuit is introduced. A single ended digital control power detection structure is used. The principle of this architecture, frequency characteristics and detection error is analyzed. The bisection technique is used to calibrate output DC offset. In this work, the frequency band is 50M~860M with –26dBm~–14dBm detection range, the settle time is 100us, the total power is 3.8mw. All the circuits in this work are designed under TSMC0.18 process. Keywords: Digital TV tuner, PGC，RSSI，Power detector，corner and temperature Compensation，DC offset calibration Classification Code: TN432

第一章概述 第一章概述 1.1研究背景及意义 现有的数字电视地面传输标准规定了射频电视调谐器（接收机）能够在很大 的输入信号动态范围内正常工作，保证数字解调需求的信噪比(SNR,如CMMB 标准的U波段信号：-95dBm~-10dBm,DVB-T信号：-90dBm~-20dBm。调谐 器同时还应满足最终输入到基带模数转换器(BBADC)的信号强度达到其最优输 入功率，此时才能保证引入较小的量化噪声。因此要求调谐器能够根据信号强度 合理设定增益[1]。调谐器广泛地集成数字自动增益控制(AGC)功能以满足上述要 求。 调谐器中往往有多个增益控制模块，图1-1显示了射频前端可变增益低噪声 放大器VGLNA)增益控制框图。增益调整的目标是LNA输出信号的强度达到预设 值。框图中检测信号强度的电路Power Detector(PWD)设计就是本文要研究的主 要内容之一。类似的，整个调谐器实现不同模块的AGC,均需要能够检测信号 强度的电路。本文研究的低中频信号强度指示电路(FRSS)和射频功率监测电 路(RF PWD)就是此类电路。 VGLNA AGC logic 图1-1低噪声放大器增益控制 1.2研究现状 信号强度检测电路有峰值检测和功率检测两种。如果调制信号如OFDM信 号存在较大均峰比问题2]，需要对检测方式做出评判。本文主要根据基于信号功 率的AGC方式设计信号功率检测电路。通常功率型AGC可以保证信号解调的 SWR,但均峰比较大时，电路容易饱和。CMOS工艺下，功率检测电路比较广 泛采用连续检测（分段线性）结构[3][4[5]，如图1-2所示，己有的文献详细讨论了 输入-输出曲线即输入功率(dBm)-输出电压()曲线的非线性误差[4][6]：工作原理 上有基于限幅放大器(Amp),有基于整流器(rectifier)限幅；对工艺、温度、器件 失配对精度的影响以及带宽限制主要集中于对放大器分析，缺少对非线性很强的 5

第一章 概述 5 第一章 概述 1.1 研究背景及意义 现有的数字电视地面传输标准规定了射频电视调谐器(接收机)能够在很大 的输入信号动态范围内正常工作，保证数字解调需求的信噪比(SNR)，如CMMB 标准的U波段信号：–95dBm~–10dBm，DVB-T信号：–90dBm~–20dBm。调谐 器同时还应满足最终输入到基带模数转换器(BBADC)的信号强度达到其最优输 入功率，此时才能保证引入较小的量化噪声。因此要求调谐器能够根据信号强度 合理设定增益[1]。调谐器广泛地集成数字自动增益控制(AGC)功能以满足上述要 求。 调谐器中往往有多个增益控制模块，图1-1显示了射频前端可变增益低噪声 放大器(VGLNA)增益控制框图。增益调整的目标是LNA输出信号的强度达到预设 值。框图中检测信号强度的电路Power Detector(PWD)设计就是本文要研究的主 要内容之一。类似的，整个调谐器实现不同模块的AGC，均需要能够检测信号 强度的电路。本文研究的低中频信号强度指示电路(IF RSSI)和射频功率监测电 路(RF PWD)就是此类电路。 VGLNA PD ADC AGC logic 图 1-1 低噪声放大器增益控制 1.2 研究现状 信号强度检测电路有峰值检测和功率检测两种。如果调制信号如 OFDM 信 号存在较大均峰比问题[2]，需要对检测方式做出评判。本文主要根据基于信号功 率的 AGC 方式设计信号功率检测电路。通常功率型 AGC 可以保证信号解调的 SNR，但均峰比较大时，电路容易饱和。CMOS 工艺下，功率检测电路比较广 泛采用连续检测(分段线性)结构[3][4][5]，如图 1-2 所示，已有的文献详细讨论了 输入-输出曲线即输入功率(dBm)-输出电压(v)曲线的非线性误差[4][6]；工作原理 上有基于限幅放大器(Amp)，有基于整流器(rectifier)限幅；对工艺、温度、器件 失配对精度的影响以及带宽限制主要集中于对放大器分析，缺少对非线性很强的