【作者】 叶芃；

【导师】 王厚军；

【作者基本信息】 电子科技大学 ， 测试计量技术及仪器， 2010， 博士

【摘要】 随着电子信息技术的不断发展,系统时钟频率成倍提高,信号时序裕度急剧减小,瞬变信号和异常问题变得突出；信号带宽增长极为迅速。信号的复杂化给以数字示波器为代表的时域测量仪器提出了新的挑战,具有足够高的信号实时捕获性能以及宽带采样能力,成为了宽带时域采集系统的两大发展方向。然而,由于受到器件以及生产工艺等方面因素的限制,如何在现有硬件条件下最大限度提高信号实时捕获能力和尽可能不失真地提高实时采样率,是宽带时域采集系统研究领域中面临的重大难题。本文结合攻读博士学位期间承担的纵向电子仪器研究任务和横向合作项目,着眼于数字三维示波器、宽带并行采样数字存储示波器等高性能测试仪器的技术实现,主要从如下几个方面展开了深入的研究：1.提高信号实时捕获能力的方法——数字三维波形映射技术。建立了数字三维映射的基本模型,深入分析了影响数字三维映射效率的各项因素,并由此得出改进的映射器阵列模型,分别提出了与各种数学模型相对应的示波器波形捕获率的计算公式。针对两种不同的映射模型,以双通道1GSPS数据采集系统为平台设计并实现了相应的数字三维示波器波形映射系统。2.数字三维示波器波形捕获率测试方法。研究了数字三维示波器波形捕获率与“死区时间”的关系,讨论了一种通过外特性对示波器波形捕获率进行测试计量的方法。通过该方法,用户或第三方能够完成实测任意一台示波器,精确得出该示波器的实际波形捕获率。同时,分别用该方法以及研究点1中讨论的波形捕获率计算公式对设计实现的数字三维示波器进行测试计量,对映射模型和映射效率计算公式进行验证。3.并行采样系统幅度误差校正方法。讨论了时间交替并行采样系统中通道失配误差的产生原因,从采集模型角度出发,研究了一种可对幅度失配误差进行综合估计与校正的方法,通过一次校正,即可同时解决偏置和增益误差的问题。4.非均匀信号重构。分析了时间交替并行采样系统中时间失配误差对信号所引入的非均匀问题,给出了非均匀条件下自适应重构的可行方案,避免了原有信号重构方法所导致的带宽损失；使用窗函数,减少频谱延拓；并讨论了非均匀下的波形重构技术与非均匀校正后的波形重构算法的资源消耗及算法效率,给出了非均匀系统综合信号重构方法。5.通道频响补偿。分析研究了数字存储示波器的带宽特性。通过系统实际通道频率响应的测试方法,奠定了从数字信号处理角度进行通道频响补偿滤波器设计的基础,并利用贝塞尔幅频响应与线性相位做进一步优化与约束,以获得更好的信号还原度。更多还原

【Abstract】 With the continuous development of the electronics and information technology,the frequency of system clock has multiplied, the timing margin has decreased sharply,and the instantaneous signal and abnormal phenomenon has become prominent; the signal bandwidth increases very rapidly.The complication of the signal presents time domain test equipment represented by digital oscilloscope a new challenge,sufficient high performance of signal real-time acquisition and the capability of broad band sampling,will be the two development orientation of the broad band time domain acquisition system.However,due to the restriction of the device and the manufacturing level,etc, under the condition of existing hardware,how to maximize the singal real time capture capability and improve the real time sampling rate as much as possible without distortion, is a major problem encountered in the research filed of broad band time domain acquisition system.This paper combines the tasks of military electronic equipment and civilian cooperation projects undertaken during the PhD research,and in view of the technology implementation of the high performance test equipment such as digital 3D oscilloscope,broad band parallel acquisizion DSO,etc, does some research on the following aspects in depth:1. Method to improve the signal real-time capture capability----technology of digital 3D mapping.The basic model of digital 3D mapping is found and varieties of factors influencing the efficiency of digital 3D mapping are analyzed deeply,as a result, the improved mapping array models are arrived,and calculating formulas of the oscilloscope waveform capture rate for the different mathematical model are put forward,respectively.For two differernt mapping models, based on 1GSPS acquisition system of 2 channel,the corresponding waveform mapping systems of the digital 3D oscilloscope are designed and implemented.2. Method to test the waveform capture rate of the digital 3D oscilloscope.The relationship between the waveform capture rate and the "dead time" is researched, and a method to test and measure the oscilloscope’s waveform capture rate with the external characteristic is discussed.Through this method,user or the third party can test any oscilloscope and obtain the actual waveform capture rate accurately.Meanwhile,the method, as well as the calculating formula of waveform capture rate mentioned above in 1),is used to test and measure digital 3D oscilloscope designed and implemented in 1),validating the mapping model and the calculating formula of the mapping efficiency.3. Method to calibrate the amplitude error of the parallel acquisition system.The reason of the channel mismatch error in parallel time-interleaved acquisition system is discussed, and from the perspective of the acquisition model, a method,which can estimate and calibrate the amplitude mismatch error synthetically,and solve the problem of offset and gain errors simultaneously through a calibration, is researched.4. Nonuniform signal reconstruction.The nonuniform problem of the signal brought about by timing mismatch error in the parallel time-interleaved acquisition system is analyzed,and the viable scheme of adaptive reconstruction under the condition of nonuniformity is introduced,which can avoid the bandwidth loss result from the former waveform reconstruction means;the spectrum continuation is reduced by using window function;the resource consumption and efficiency of the waveform reconstruction technology with nonuniformity and the waveform reconstruction arithmetic after the nonuniform calibration is analyzed, and the integration signal reconstruction method of nonuniform system is exposed to optimize the arithmetic efficiency.5. Compensation for channel frequency response.The bandwidth characteristic of DSO is analyzed and researched.The method to test the actual channel frequency response of the system is present, which establishes a base of the design of filter compensating for channel frequency respone from the perspective of digital signal processing, meanwhile,the best degree of the signal recovery can be obtained by using the Bassel amplitude-frequency response and linear phase to do furture optimization and restriction.更多还原