便携式DDS信号源设计

发布时间：2018-07-03 13:12

本文选题：便携式 + DDS　；参考：《华中师范大学》2015年硕士论文

【摘要】：信号源是科学实验和工程界最常用的测试测量仪器之一,广泛应用于通信、雷达和军事等领域,对各种高性能信号源研究至今仍然是仪器行业中的热点。而数字化直接频率合成技术,即DDS(Direct Digital Synthesis),以其频率分辨率高、频率响应速度快以及相位连续等优点,广泛应用于高性能信号源的研究中。目前,市场上DDS信号源几乎都是台式信号源,而台式信号源功耗高、体积大且不便携带。为满足部队野外作业、车载移动平台等对信号源的特殊要求,受江苏绿扬电子仪器集团有限公司所托,研究开发一种低功耗便携式DDS信号源。低功耗便携式DDS信号源研发的主要技术问题是选择合适的低功耗DDS信号产生方案。本文在研究分析了现有DDS技术方案的基础上,提出了采用STM32控制DAC5686专用芯片的低功耗方案。该芯片的低功耗是靠低工作电压实现的,因此,必须采用高效多路开关电源供电系统。然而,开关电源又严重影响信号源要求的模拟小信号输出。为解决这一问题,本文在电源完整性和信号完整性方面也做了大量的研究。论文详细分析了目前主流的FPGA控制高速D/A转换器及传统的DDS专用集成电路的DDS信号源技术解决方案。分析了各自的功率消耗,估算了基于DAC5686芯片的DDS信号源整机供电电压、电流及电源效率,介绍了相关硬件电路的设计,并对关键的滤波电路进行了仿真。论文还详尽地阐述了该DDS信号源的控制软件和人机界面的设计思想,并绘出了软件流程图。论文最后对DDS信号源整机进行了测试,结果显示该信号源采样率高达310MSa/s,模拟带宽达120MHz,最小输出信号达10mVpp,且功耗仅为2.25W,并可输出多种调制波,满足用户提出的技术指标要求。
[Abstract]:Signal source is one of the most commonly used measurement instruments in the field of science experiment and engineering. It is widely used in the fields of communication radar and military and so on. The research on various high performance signal sources is still a hot spot in the instrument industry. Digital direct frequency synthesis (DDS) is widely used in the research of high performance signal sources due to its advantages of high frequency resolution, fast frequency response and continuous phase. At present, almost all DDS signal sources in the market are desktop signal sources, while desktop signal sources have high power consumption, large volume and inconvenient to carry. In order to meet the special requirements of the field operation and the on-board mobile platform, a low-power portable DDS signal source was developed by Jiangsu Luyang Electronic instrument Group Co., Ltd. The main technical problem of low power portable DDS signal source is to select suitable low power DDS signal generation scheme. Based on the research and analysis of the existing DDS technology, this paper proposes a low power scheme using STM32 to control the DAC5686 chip. The low power consumption of the chip is realized by low working voltage. Therefore, it is necessary to adopt an efficient switching power supply system. However, the switching power supply seriously affects the analog small signal output required by the signal source. In order to solve this problem, this paper has done a lot of research on power integrity and signal integrity. This paper analyzes the current mainstream FPGA control high speed D / A converter and traditional DDS ASIC DDS signal source technology solutions. The power consumption of DDS signal generator based on DAC5686 is analyzed, the supply voltage, current and power efficiency of DDS signal source are estimated, the design of related hardware circuit is introduced, and the key filter circuit is simulated. The control software of the DDS signal source and the design idea of the man-machine interface are described in detail, and the flow chart of the software is given. Finally, the DDS signal generator is tested. The results show that the sampling rate of the DDS signal source is as high as 310 Ma / s, the analog bandwidth is 120 MHz, the minimum output signal is 10 mVppand the power consumption is only 2.25W, and it can output various modulation waves, which can meet the technical requirements proposed by the user.
【学位授予单位】：华中师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN741

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