可编程增益放大器及电流模复数带通滤波器的设计与实现

发布时间：2018-06-30 07:33

  本文选题：可编程增益放大器 + 共模反馈　； 参考：《东南大学》2015年硕士论文

【摘要】：全球数字广播(Digital Radio Mondiale, DRM)和数字音频广播(Digital Audio Broadcasting, DAB)是世界范围内被广泛应用的数字广播标准。研究基于这两种标准的接收机芯片可以提升我国无线通信芯片的核心竞争力,具有重大意义。DRM接收芯片分为两次变频低中频架构。本文的研究对象是应用于DRM/DAB接收机第二中频(fc=2.048 MHz)的可编程增益放大器(Programable Gain Amplifier, PGA)和电流模复数带通滤波器(Current-Mode Complex Band-Pass Filter)电路。PGA是保证接收机正常工作、具有较大输入动态范围的重要模块。本文的PGA采用的是基于运(算)放(大器)的闭环反馈结构。运放是两级全差分结构,采用密勒电容进行相位补偿。采用AB类输出级来扩大PGA的输出动态范围和降低静态功耗。另外,采用低增益的DCOC反馈回路来稳定PGA的直流工作点,同时保证反馈环路的稳定性。PGA的工作带宽大于10 MHz,增益范围10～50 dB,步长l dB,带内增益波动小于0.5 dB。当增益为10 dB时,IP1dB大于-5 dBm。本文的另一个主要工作是设计带有镜像频率抑制功能的电流模滤波器。滤波器的输入和输出均为电流信号。文中的滤波器是一个3阶切比雪夫Ⅰ型有源RC滤波器,其中心频率为2 MHz,通带带宽1.6 MHz,带内波动小于3 dB,邻近信道抑制(ACS@6 MHz)和镜像频率抑制(IRR@ 2 MHz)大于35 dB。电流模滤波器的核心模块是全差分电流放大器,该电流放大器采用第二代电流传输器CCⅡ(Current ConveyorⅡ)来实现。此外,设计中还引入了可编程电容阵列来实现滤波器的调谐。最后,采用中芯国际SMIC 0.18μm CMOS工艺实现了PGA和滤波器的电路,并进行了流片测试。测试结果基本满足设计指标要求。同时,分析了测试结果,对进一步的工作提出了建议。
[Abstract]:Digital Radio broadcast (DRM) and Digital Audio Broadcasting (DAB) are widely used in the world. The research on the receiver chip based on these two standards can enhance the core competitiveness of the wireless communication chip in China. It is of great significance that the DRM receiver chip can be divided into two frequency conversion low intermediate frequency architectures. The research object of this paper is the programmable gain amplifier (PGA) and the Current-Mode complex Band-Pass filter (PGA) circuit, which are applied to the second intermediate frequency (fc=2.048 MHz) of DRM / DAB receiver. Important modules with large input dynamic range. The PGA in this paper adopts a closed loop feedback structure based on operational (computational) amplifier. The operational amplifier is a two-stage fully differential structure with Miller capacitor for phase compensation. Class AB output stage is used to expand the dynamic range of PGA output and reduce static power consumption. In addition, the DCOC feedback loop with low gain is used to stabilize the DC operating point of PGA. At the same time, the stability of the feedback loop. The bandwidth of PGA is larger than 10 MHz, the gain range is 1050 dB, the step is 1 dB, and the in-band gain fluctuation is less than 0.5 dB. When the gain is 10 dB, the IP 1dB is greater than -5 dBm. Another main work of this paper is to design a current-mode filter with mirror frequency suppression function. The input and output of the filter are current signals. The filter in this paper is a third-order Chebyshev type I active RC filter with a central frequency of 2 MHz, a passband bandwidth of 1.6 MHz, an in-band fluctuation of less than 3 dB, a proximity channel suppression (ACSR @ 2 MHz) and a mirror frequency suppression (IRR @ 2 MHz) of more than 35 dB. The core module of current-mode filter is fully differential current amplifier, which is implemented by current Conveyor 鈪，

本文编号：2085510