学校代码：10246 学号：11212020007 復g大年 硕士学位论文 (科学学位) 数字电视接收系统中射频前端电路研究与设计 Research and Design on RF Front-end Circuit of Digital TV Receiver System 院 系： 微电子研究院 专 业： 微电子学与固体电子学 姓 名： 程涛 指导老师： 唐长文教授 完成日期： 2014年04月11日
学校代码：10246 学号：11212020007 t 硕 士 学 位 论 文 （科学学位） 数字电视接收系统中射频前端电路研究与设计 Research and Design on RF Front-end Circuit of Digital TV Receiver System 院 系： 微电子研究院 专 业： 微电子学与固体电子学 姓 名： 程涛 指 导 老 师： 唐长文 教授 完 成 日 期： 2014 年 04 月 11 日
目录 图目录 表目录… M 摘要… …1 Abstract… …2 第一章绪论… …3 1.1研究背景… …3 1.2论文研究内容与贡献… …4 1.3论文组织结构 …4 第二章射频前端系统指标分析… …5 2.1一般系统指标分析… …5 2.1.1与噪声相关的性能指标 …5 2.1.2与非线性相关的性能指标…9 2.1.3其它指标… 2.2级联系统指标分析… …18 2.2.11dB增益压缩点级联分析 19 2.2.2线性度级联分析 20 2.2.3噪声系数级联分析… 21 2.3接收机架构的选择… 22 2.3.1接收机架构的历史演变过程 22 2.3.2零中频接收机优缺点分析 27 第三章低噪声放大器研究与设计… 29 3.1前言… 29 3.2传统低噪声放大器的结构… 29 3.2.1共栅低噪声放大器… 29 3.2.2三种共源低噪声放大器 31 3.3低噪声放大器的性能优化…。 34 3.3.1噪声优化技术… 34 3.3.2线性度优化技术… …37 3.3.3可变增益情况下输入匹配优化技术…41 3.4一种可变增益的宽带低噪声放大器设计… 43 3.4.1设计指标与整体设计考虑… 43
I 目 录 图目录 ·························································································III 表目录 ························································································ VI 摘 要 ··························································································1 Abstract ·······················································································2 第一章 绪论 ·················································································3 1.1 研究背景 ···········································································3 1.2 论文研究内容与贡献····························································4 1.3 论文组织结构·····································································4 第二章 射频前端系统指标分析·························································5 2.1 一般系统指标分析·······························································5 2.1.1 与噪声相关的性能指标················································5 2.1.2 与非线性相关的性能指标·············································9 2.1.3 其它指标································································16 2.2 级联系统指标分析·····························································18 2.2.1 1 dB 增益压缩点级联分析··········································19 2.2.2 线性度级联分析·······················································20 2.2.3 噪声系数级联分析····················································21 2.3 接收机架构的选择·····························································22 2.3.1 接收机架构的历史演变过程········································22 2.3.2 零中频接收机优缺点分析···········································27 第三章 低噪声放大器研究与设计····················································29 3.1 前言 ···············································································29 3.2 传统低噪声放大器的结构····················································29 3.2.1 共栅低噪声放大器····················································29 3.2.2 三种共源低噪声放大器··············································31 3.3 低噪声放大器的性能优化····················································34 3.3.1 噪声优化技术··························································34 3.3.2 线性度优化技术·······················································37 3.3.3 可变增益情况下输入匹配优化技术·······························41 3.4 一种可变增益的宽带低噪声放大器设计··································43 3.4.1 设计指标与整体设计考虑···········································43
3.4.2高增益模块设计考虑… …45 3.4.3衰减器设计考虑…50 3.4.4高增益模块的性能优化…52 第四章下变频混频器研究与设计…55 4.1前言… 55 4.2有源混频器到电流驱动型无源混频器的过渡… 55 4.3电流驱动型无源混频器的性能分析… 57 4.3.1增益和阻抗特性分析……… 58 4.3.2噪声分析… 61 4.3.3非线性分析… 67 4.4一种可变增益电流驱动型无源混频器设计… 67 4.4.1整体架构与设计指标… 67 4.4.2跨导单元与混频器开关设计考虑… 68 4.4.3混频器开关管的偏置设计考虑· …… 71 4.4.4跨阻运算放大器设计考虑… 72 第五章芯片实现与仿真测试结果… 77 5.1低噪声放大器与混频器级联仿真结果 77 5.1.1最高增益与噪声系数仿真结果…77 5.1.2线性度级联仿真结果… 78 5.2射频前端电路芯片实现 79 5.3芯片测试结果… 80 5.3.1噪声系数测试结果… 80 5.3.2线性度测试结果… …81 5.3.3衰减器增益台阶以及S11测试结果…82 5.3.4性能总结与对比 83 第六章设计总结与展望… 85 6.1设计总结… 85 6.2展望… 86 参考文献… …87 致谢… …91
II 3.4.2 高增益模块设计考虑·················································45 3.4.3 衰减器设计考虑·······················································50 3.4.4 高增益模块的性能优化··············································52 第四章 下变频混频器研究与设计····················································55 4.1 前言 ···············································································55 4.2 有源混频器到电流驱动型无源混频器的过渡····························55 4.3 电流驱动型无源混频器的性能分析········································57 4.3.1 增益和阻抗特性分析·················································58 4.3.2 噪声分析································································61 4.3.3 非线性分析·····························································67 4.4 一种可变增益电流驱动型无源混频器设计·······························67 4.4.1 整体架构与设计指标·················································67 4.4.2 跨导单元与混频器开关设计考虑··································68 4.4.3 混频器开关管的偏置设计考虑·····································71 4.4.4 跨阻运算放大器设计考虑···········································72 第五章 芯片实现与仿真测试结果 ·····················································77 5.1 低噪声放大器与混频器级联仿真结果·····································77 5.1.1 最高增益与噪声系数仿真结果·····································77 5.1.2 线性度级联仿真结果·················································78 5.2 射频前端电路芯片实现·······················································79 5.3 芯片测试结果···································································80 5.3.1 噪声系数测试结果····················································80 5.3.2 线性度测试结果·······················································81 5.3.3 衰减器增益台阶以及 S11 测试结果······························82 5.3.4 性能总结与对比·······················································83 第六章 设计总结与展望 ·································································85 6.1 设计总结 ·········································································85 6.2 展望 ···············································································86 参考文献 ·····················································································87 致谢 ···························································································91
图目录 图2-1手工计算噪声系数时的等效电路 …6 图2-2静态非线性的主要来源…9 图2-3单频点激励下的输出频谱示意图 …10 图2-4双频点激励下输出频谱示意图… …13 图2-5lP3实际测试图… …15 图2-6带外两个不同幅度的非线性输入情况下输出频谱示意图…16 图2-7SFDR等参数综合示意图…18 图2-8两级级联系统…… …19 图2-9原始超外差接收机系统架构…23 图2-10LO信号高位注入时镜像干扰的影响… 24 图2-11加入频带选择和镜像抑制滤波器后的超外差接收机…24 图2-12二次下变频接收机系统架构… 25 图2-13零中频接收机中自混叠现象… 26 图2-14当前流行的二次变频接收机架构… 26 图2-15零中频接收机架构… 27 图2-16L0信号与射频输入信号通路之间的耦合… 28 图3-1共栅低噪声放大器… 30 图3-2带并联输入阻抗的共源低噪声放大器…31 图3-3带电阻反馈的共源低噪声放大器… 32 图3-4带源极电感负反馈的共源低噪声放大器…33 图3-5增益提高技术应用于共栅低噪声放大器… 35 图3-6交叉耦合共栅低噪声放大器简单示意图…35 图3-7噪声抵消的基本原理及其应用 36 图3-8带反馈的共栅放大器…37 图3-9单个MOS管的gm与V6s之间的关系… 38 图3-10K2an和Kg与V6s之间的关系… 9 图3-11K2gn和Kgn与6s之间的关系… 39 图3-12分析反馈对线性度影响的模型…41 图3-13研究可变增益对输入匹配影响的小信号模型…42 图3-14可变增益情况下输入匹配优化的新结构模型…42 图3-15可变增益宽带低噪声放大器整体架构……44 图3-16用于高增益和中间增益通路的有源负反馈低噪声放大器…45
III 图目录 图 2-1 手工计算噪声系数时的等效电路 ··············································6 图 2-2 静态非线性的主要来源···························································9 图 2-3 单频点激励下的输出频谱示意图 ············································10 图 2-4 双频点激励下输出频谱示意图 ···············································13 图 2-5 IIP3 实际测试图··································································15 图 2-6 带外两个不同幅度的非线性输入情况下输出频谱示意图 ··············16 图 2-7 SFDR 等参数综合示意图······················································18 图 2-8 两级级联系统·····································································19 图 2-9 原始超外差接收机系统架构 ··················································23 图 2-10 LO 信号高位注入时镜像干扰的影响······································24 图 2-11 加入频带选择和镜像抑制滤波器后的超外差接收机···················24 图 2-12 二次下变频接收机系统架构·················································25 图 2-13 零中频接收机中自混叠现象·················································26 图 2-14 当前流行的二次变频接收机架构···········································26 图 2-15 零中频接收机架构·····························································27 图 2-16 LO 信号与射频输入信号通路之间的耦合································28 图 3-1 共栅低噪声放大器·······························································30 图 3-2 带并联输入阻抗的共源低噪声放大器 ······································31 图 3-3 带电阻反馈的共源低噪声放大器 ············································32 图 3-4 带源极电感负反馈的共源低噪声放大器 ···································33 图 3-5 增益提高技术应用于共栅低噪声放大器 ···································35 图 3-6 交叉耦合共栅低噪声放大器简单示意图 ···································35 图 3-7 噪声抵消的基本原理及其应用 ···············································36 图 3-8 带反馈的共栅放大器····························································37 图 3-9 单个 MOS 管的 gm 与 VGS 之间的关系 ·····································38 图 3-10 2gm K 和 3gm K 与 VGS 之间的关系 ·············································39 图 3-11 2gm K 和 3gm K 与 VDS 之间的关系 ·············································39 图 3-12 分析反馈对线性度影响的模型··············································41 图 3-13 研究可变增益对输入匹配影响的小信号模型····························42 图 3-14 可变增益情况下输入匹配优化的新结构模型····························42 图 3-15 可变增益宽带低噪声放大器整体架构·····································44 图 3-16 用于高增益和中间增益通路的有源负反馈低噪声放大器 ············45
图3-17恒定-gm自偏置电路结构… …46 图3-18局部环路增益与P3之间的关系 49 图3-19反馈晶体管的非线性如何影响输出三阶交调量… 50 图3-20衰减器模块的电路结构…51 图3-21可变增益情况下的匹配优化结构… .… 53 图3-22可变增益情况下输入匹配优化前后对比… 53 图4-1单平衡有源混频器… 56 图4-2通过减小被混频的直流信号来减小1/f噪声的方法…56 图4-3单平衡电流驱动型无源混频器… … 57 图4-4电流驱动型无源混频器的分析模型… 57 图4-5计算增益时的混频器等效电路…59 图4-6电流驱动型无源混频器输入阻抗分析模型… 60 图4-7跨导单元白噪声分析模型… 62 图4-8混频器跨阻放大器白噪声分析模型 … 63 图4-9跨导单元的1/f噪声分析模型……65 图4-10失调电压影响本地振荡波示意图… 65 图4-11存在失调电压时差分输出噪声电流情况… 66 图4-12电流驱动型无源混频器的结构。 68 图4-13跨导单元与混频器开关电路原理图… 69 图4-14开关电容密勒补偿与传统负载电容补偿波特图对比 70 图4-15混频器开关的导通交叠与闭合交叠…71 图4-16混频器开关栅极直流偏置产生电路…72 图4-17 Class AB输出级结构原理图… 73 图4-18带Class AB输出级的全差分运算放大器…75 图5-1级联系统最大增益仿真结果 77 图5-2级联系统噪声系数仿真结果…77 图5-3高增益LNA模式下射频前端IP3仿真结果 78 图5-4低增益LNA模式下射频前端lP3仿真结果… …78 图5-5射频前端电路在零中频数字电视接收系统中的实现框图 79 图5-6射频前端电路芯片照片…79 图5-7使用9030A信号分析仪测量整个接收机的噪声系数示意图…80 图5-8噪声系数测试结果… 80 图5-9双音测试频谱输出图…81 图5-10高增益LNA模式下的lP3测试曲线……81 图5-11低增益LNA模式下的P3测试曲线…82
IV 图 3-17 恒定-gm 自偏置电路结构 ·····················································46 图 3-18 局部环路增益与 IIP3 之间的关系··········································49 图 3-19 反馈晶体管的非线性如何影响输出三阶交调量·························50 图 3-20 衰减器模块的电路结构·······················································51 图 3-21 可变增益情况下的匹配优化结构···········································53 图 3-22 可变增益情况下输入匹配优化前后对比··································53 图 4-1 单平衡有源混频器·······························································56 图 4-2 通过减小被混频的直流信号来减小 1/f 噪声的方法 ·····················56 图 4-3 单平衡电流驱动型无源混频器 ···············································57 图 4-4 电流驱动型无源混频器的分析模型 ·········································57 图 4-5 计算增益时的混频器等效电路 ···············································59 图 4-6 电流驱动型无源混频器输入阻抗分析模型 ································60 图 4-7 跨导单元白噪声分析模型······················································62 图 4-8 混频器跨阻放大器白噪声分析模型 ·········································63 图 4-9 跨导单元的 1/f 噪声分析模型·················································65 图 4-10 失调电压影响本地振荡波示意图···········································65 图 4-11 存在失调电压时差分输出噪声电流情况··································66 图 4-12 电流驱动型无源混频器的结构··············································68 图 4-13 跨导单元与混频器开关电路原理图········································69 图 4-14 开关电容密勒补偿与传统负载电容补偿波特图对比···················70 图 4-15 混频器开关的导通交叠与闭合交叠········································71 图 4-16 混频器开关栅极直流偏置产生电路········································72 图 4-17 Class AB 输出级结构原理图················································73 图 4-18 带 Class AB 输出级的全差分运算放大器································75 图 5-1 级联系统最大增益仿真结果 ··················································77 图 5-2 级联系统噪声系数仿真结果 ··················································77 图 5-3 高增益 LNA 模式下射频前端 IIP3 仿真结果 ······························78 图 5-4 低增益 LNA 模式下射频前端 IIP3 仿真结果 ······························78 图 5-5 射频前端电路在零中频数字电视接收系统中的实现框图 ··············79 图 5-6 射频前端电路芯片照片·························································79 图 5-7 使用 9030A 信号分析仪测量整个接收机的噪声系数示意图··········80 图 5-8 噪声系数测试结果·······························································80 图 5-9 双音测试频谱输出图····························································81 图 5-10 高增益 LNA 模式下的 IIP3 测试曲线······································81 图 5-11 低增益 LNA 模式下的 IIP3 测试曲线······································82