Abstract
Abstract
With the development of electronic science and technology, there is much more focus on it, and its development has huge relationship with the measurement technology; Spectrum analyzer is an important part of the measurement technology. And the different spectrum analyzers which test the signals in the different circumstances have the significant meaning.Our spectrum analyzer is to measure the signals of noise, audio, mechanism and so on. In this paper, our designed virtual spectrum is based on the teaching and gives the students the profundity impression. Based on this purpose，We design this solo channel of spectrum analyzer.
My virtual spectrum analyzer designed on the SJ8002_B platform, previous on the data acquisition module in the platform, and as the software tools of LabVIEW to design it .At first, the paper instroduces the whole things of virtual spectrum analyzer, the meaning of development and research, then discussed the details of its hardware and software designing.
On the hardware part, data acquisition-in this part I changed the 8 bits ADC to 12 bits one and rejusted its peripheral circuits.Second, communication module, which communicated the computer with platform, and use the USB-EPP model.Third, Store and control module, which controls the data acquisition module and storing the data by FPGA.
On the software part, we designed it on module, and descript the methods of the programming and flow chart in details, then I designed the virtual spectrum analyzer?s control panel,data acquisition module and FFT module by LabVIEW.and finally make it achieve functional.
Key words: Virtual spectrum analyzer; data acquisition; FPGA; LabVIEW; FFT
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目录
目 录
第一章 绪论 ......................................................... 1
1.1 项目背景与课题研究意义 ....................................... 1 1.2 国内外发展状况 ............................................... 2 1.3 通用测试平台简介 ............................................. 3 1.4 课题的主要技术指标 ........................................... 4 1.5 课题的主要工作 ............................................... 5 第二章 虚拟频谱仪硬件电路设计 ....................................... 6
2.1 硬件总体结构 ................................................. 6 2.2 输入通道设计 ................................................. 7
2.2.1增益控制电路 ............................................ 7 2.2.2差分电路 ................................................ 9 2.3 A/D转换器的设计 ............................................ 11
2.3.1 模数转换器的选择 ...................................... 12 2.3.2 AD转换器的接口设计 ................................... 13 2.4 存储电路 .................................................... 15 2.5 通信接口设计 ................................................ 16
2.5.1 USB串行转并行接口 .................................... 16 2.5.2 通信接口的软硬件设计 .................................. 17
2.5.2.1 通信接口的硬件设计 ............................... 17 2.5.2.2 通信接口的软件设计 ............................... 19
2.6 本章小结 .................................................... 21 第三章 采集时序控制逻辑设计 ....................................... 22
3.1 ADC采样时钟的选择和使用 ................................... 22 3.2 触发控制电路 ................................................ 22
3.2.1 触发方式的设计 ........................................ 22 3.2.2触发源的设计 ........................................... 23 3.3 FPGA的概述 ................................................ 24 3.4 设计中FPGA的使用及其程序设计 .............................. 24
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目录
3.4.1 存储电路的总体设计 .................................... 25 3.4.2 逻辑电路的地址分配 .................................... 28 3.4.3 采集通路的参数设置电路 ................................ 29 3.4.4 触发控制电路的设计 .................................... 30 3.4.5 降频累加器的电路设计 .................................. 31 3.5 本章小结 .................................................... 33 第四章 虚拟数字频谱仪软件设计 ...................................... 34
4.1 前面板窗口和框图程序窗口 .................................... 34
4.1.1 VI库 .................................................. 34 4.1.2 动态链接库（DLL） .................................... 35 4.2 基于FFT算法的频谱分析仪设计 ................................ 35
4.2.1 傅立叶变换 ............................................ 36 4.2.2 FFT理论 .............................................. 37 4.2.3 窗函数 ................................................ 39 4.3 频谱分析仪驱动软件设计 ...................................... 42 4.4 频谱分析仪的软件流程设计 .................................... 46
4.4.1 频谱分析仪指标 ........................................ 47 4.4.2 面板与程序框图 ........................................ 48 4.5 误差分析基础 ................................................ 54
4.5.1 混叠误差 .............................................. 54 4.5.2 频谱泄漏 .............................................. 54 4.5.3 栅栏效应 .............................................. 55 4.6 本章小结 .................................................... 55 第五章 软硬件调试与测试结果 ........................................ 56
5.1 抗干扰设计 .................................................. 56
5.1.1合理的布局布线 ......................................... 56 5.1.2合理接地 ............................................... 56 5.1.3电源去耦与滤波 ......................................... 57 5.2 系统的调试 ................................................. 57
5.2.1硬件调试 ............................................... 57 5.2.2软件调试 ............................................... 58 5.3 测试结果 .................................................... 58
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目录
结 束 语 ........................................................... 64 致 谢 ........................................................... 66 参考文献 ........................................................... 67 个人简介 ........................................................... 68
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