DRM接收机中可变增益放大器研究与设计

发布时间：2018-02-16 04:56

本文关键词： 可变增益放大器高线性度低噪声指数控制电压　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着数字技术、4G网络以及互联网等新型传输媒体的普及,模拟广播因其固有的缺点而面临越来越严峻的挑战,模拟广播的数字化是克服其诸多缺点的最佳选择。全球数字广播系统(Digital Radio Mondiale,DRM)是目前发展最快的数字广播系统标准。DRM系统的优势在于可以给用户更多无失真的音频体验、降低设备的功耗和成本并降低电磁污染。因此,DRM接收机系统的研究对我国数字无线广播事业的发展具有重要意义。本文研究和设计了应用于DRM接收机中射频前端的VGA(Variable Gain Amplifier)即可变增益放大器电路。为了实现低功耗和低成本的电路设计要求,本文采用CMOS(Complementary Metal-Oxide-Semiconductor)即互补式金属氧化物半导体工艺进行电路设计。系统规划要求可变增益放大器的增益与控制电压呈dB线性关系并且需要较大的增益调节范围、低增益时较高的输入线性度、高增益时较低的噪声、低功耗等性能指标。为了能够使VGA具有较大的增益调节范围,采用两级串联的Gilbert乘法器单元作为可变增益放大器的增益单元,通过改变乘法器两路尾电流的大小实现放大器的增益可调特性；为了让放大器的增益与控制电压呈dB线性关系,利用工作在线性区的MOSFET(MOS Field-Effect Transistor)即MOS场效应管所具有的电流电压逼近指数函数的特性产生指数控制电压。本设计的VGA采用SMIC 0.18-μm CMOS工艺完成了版图设计。后仿真结果表明此可变增益放大器符合主要设计要求。
[Abstract]:With the popularity of digital technology, 4G networks and new transmission media such as the Internet, analog broadcasting is facing more and more serious challenges because of its inherent shortcomings. The digitalization of analog broadcasting is the best choice to overcome its many shortcomings. Digital Radio mondialear DRM is the fastest developing digital broadcasting system standard at present. The advantage of digital broadcasting system is that it can give users more audio experience without distortion. Therefore, the research of DRM receiver system is of great significance to the development of digital radio broadcasting in China. This paper studies and designs RF front-end used in DRM receiver. To achieve low power and low cost circuit design requirements, In this paper, CMOS(Complementary Metal-Oxide-Semiconductor process is used to design the circuit. The system planning requires that the gain of the VGA has a dB linear relationship with the control voltage and requires a large range of gain regulation. High input linearity at low gain, low noise at high gain, low power consumption and so on. The two-stage series Gilbert multiplier unit is used as the gain unit of the variable gain amplifier. The gain adjustable characteristic of the amplifier is realized by changing the size of the tail current of the multiplier, and the gain of the amplifier is linearly correlated with the control voltage. The exponential control voltage is generated by the characteristic of current and voltage approaching exponential function of MOS FET, which works in the linear region of MOSFET(MOS Field-Effect Transistor. The layout design of VGA is completed by SMIC 0.18- 渭 m CMOS process. The post-simulation result table is given. This variable gain amplifier meets the main design requirements.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722;TN934.3

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