摘要中频信号在通信、雷达、图像处理等应用领域应用极其广泛。在数字信号处理中，对中频信号的高速采样已经成为了信号处理的必要前提，是后续数字信号处理的基础。 论文主要完成中频信号高速采样系统的设计与实现，系统输入的信号是载波频率为15MHz，带宽6MHz 的 AM 信号。系统主要由高速 ADC，采样控制模块，数字下变频模块等组成。ADC部分用 Altium Desinger 设计电路，包括了单端转差分、电源电路、时钟电路、AD 采样电路等，输出 12bit 采样数据。数字下变频模块包括 NCO、乘法器、FIR滤波模块；在 Quartuas II 平台编写 ADC控制程序，利用 Singaltap II 在线逻辑分析仪抓取采样后信号波形；数字下变频相关模块仿真通过配置 IP 核，经由 Modelsim 仿真测试。通过调用 MATLAB 中的 Simulink 完成系统级的仿真，验证了方案的正确性。 28457
毕业论文关键词 中频信号 高速采样 数字下变频 FIR滤波器 数控振荡器
Title Design of high-speed sampling system for IF signal Abstract Intermediate Frequency (IF) signal has been applied widely in communication, radar, image processing and other applications. In digital signal processing, high-speed sampling of IF signal has become a necessary requirement for signal processing, and is the basis of digital signal processing. This paper is designed to complete a high-speed sampling system of IF signal, the input signal is the carrier frequency 15MHz, 6MHz bandwidth frequency of the AM signal. The system main contains high-speed ADC, sampling control, DDC, and system simulation. ADC section designed with Altium Desinger, including the Single ended to differential circuit, Power circuit, Clock circuit, AD sampling circuit. The output sampling data is 12bit, and crawl demodulated waveform with Singaltap II. DDC part include NCO, Multipliers, FIR filter modules. ADC control program and the Verilog HDL program of DDC parts are writed in Quartuas II platform and simulated via Modelsim . Finally, By calling in MATLAB Simulink system-level simulation to verify the correctness of the program. High-speed AD sampling is the first step in digital signal processing, and is the basis of digital signal processing. Keywords Intermediate Frequency High-speed sampling Digital down conversion FIR NCO
目 次
1 绪论 . 1
1.1 研究目的及意义 1
1.2 国内外研究概况 1
1.3 数字信号处理结构 2
1.4 本文研究内容与章节安排 4
2 中频采样电路 . 5
2.1 总体方案设计 5
2.2 硬件模块 6
2.2.1 A/D采样模块 6
2.2.2 单端转差分电路 7
2.2.3 时钟电路 8
2.2.4 电源电路 9
2.2.5 A/D采样板 . 11
2.3 FPGA 开发系统 . 12
2.3.1 FPGA特点及开发流程 . 12
2.3.2 FPGA开发平台 . 13
2.4 本章总结 . 14
3 系统原理及模块仿真 15
3.1 采样原理 . 15
3.1.1 低通采样 . 15
3.1.2 带通采样 . 17
3.3 AM 调制信号 . 18 中频信号高速采样系统的设计与实现:http://www.751com.cn/tongxin/lunwen_23303.html