基于AD9957的任意波形发生器的设计与实现

发布时间：2018-07-15 18:06

【摘要】：任意波形发生器用于产生各种制式的发射信号或者测试信号,在雷达、航天等领域具有重要的作用。传统的信号发生器是基于模拟电子技术的,并且波形通常是规则的。在现代电子系统中,要求能现场输出任意形式的信号,所以任意波形发生器就具有了重要的研究和应用价值。论文将直接数字频率合成技术、数字正交上变频技术和高速串行数据传输技术结合在一起,以现场可编程门阵列和正交上变频芯片AD9957为硬件基础,通过系统硬件电路设计和软件编程,完成了任意波形发生器的设计与实现。首先,论文分析了DDS原理和数字正交调制原理,对DDS输出的频谱和相位舍入引起的杂散进行了推导,阐述了一种工程上容易实现并且性能较好的积分级联梳状(CIC)滤波器。基于任意波形发生器理论,深入研究了数字正交上变频器AD9957的芯片架构、三种工作模式以及内部信号处理链路。其次,论文给出了任意波形发生器的硬件电路设计和软件编程实现。在硬件设计中,完成了电源网络、AD9957应用电路以及光纤通信接口的设计。在FPGA软件编程中,完成了AD9957功能配置模块和光纤通信模块的设计,并对QDUC模式下,基带数据接收处理的方法进行了详细的说明。最后,论文给出了系统的调试结果,包括光纤通信测试和AD9957的调试。在光纤通信调试中,验证了光纤收发数据的功能并对数据误码进行了测试。在AD9957的测试中,对其单音模式、插值DAC模式以及QDUC模式都进行了调试,给出了正弦信号、线性调频信号和调幅信号的波形测试图和频谱测试图,计算了实际输出信号与设定信号的误差,测试结果表明该任意波形发生器具有输出信号频率高、误差小、信号更新快等特点。
[Abstract]:Arbitrary waveform generator is used to generate various transmission signals or test signals, which plays an important role in radar, aerospace and other fields. Traditional signal generators are based on analog electronics, and waveforms are usually regular. In modern electronic system, it is required to output any form of signal in the field, so arbitrary waveform generator has important research and application value. This paper combines direct digital frequency synthesis technology, digital orthogonal up-conversion technology and high-speed serial data transmission technology, and takes field programmable gate array and orthogonal up-conversion chip AD9957 as the hardware foundation. Through the system hardware circuit design and software programming, the design and implementation of arbitrary waveform generator are completed. Firstly, the principle of DDS and the principle of digital quadrature modulation are analyzed, the spurious caused by frequency spectrum and phase rounding of DDS output is deduced, and a kind of integrated cascaded comb (CIC) filter which is easy to realize in engineering and has better performance is described. Based on the theory of arbitrary waveform generator, the chip architecture, three working modes and internal signal processing link of AD9957 digital quadrature upconverter are studied. Secondly, the paper gives the hardware circuit design and software programming of arbitrary waveform generator. In the hardware design, the application circuit of power network AD9957 and the optical fiber communication interface are designed. In the FPGA software programming, the AD9957 function configuration module and the optical fiber communication module are designed, and the method of receiving and processing the baseband data in QDuc mode is explained in detail. Finally, the debugging results of the system are given, including optical fiber communication test and AD9957 debugging. In the debugging of optical fiber communication, the function of receiving and sending data in optical fiber is verified and the error code of data is tested. In the test of AD9957, the single tone mode, interpolation DAC mode and QDuc mode are all debugged, and the waveform test diagram and spectrum test diagram of sinusoidal signal, linear frequency modulation signal and amplitude modulation signal are given. The error between the actual output signal and the set signal is calculated. The test results show that the arbitrary waveform generator has the characteristics of high output signal frequency, small error and fast signal updating.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN741

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