基于"NTN"技术的宽带取样示波器的校准

介绍了用于校准宽带取样示波器的详尽模型法和脉冲标准法 ,并指出了它们的缺陷。着重介绍了可以进行自校准的“NTN”技术 ,该技术的基本设计是将三台取样示波器以“NTN”形式两两对接 ,其中一台对直流进行采样 ,用反卷积分离另一台取样示波器的响应波形 ,并通过解方程组可得到示波器的冲激响应。最后给出了用反卷积分离取样示波器冲激响应的计算机仿真。     

基于NTN技术的宽带取样示波器带宽不确定度的研究

NTN技术是一种校准宽带取样示波器的新方法,其提供的测量量是kick-out脉冲响应(显示)波形数据,而宽带取样示波器的带宽是对kick-out脉冲响应波形数据进行反卷积分离等处理获得的导出量.提出了一种基于NTN技术的宽带取样示波器带宽不确定度的评定方法.首先分析了NTN技术引入不确定度的主要因素;然后提出了由测量量导出带宽的不确定度的传递算法流程,并推导了线性内插的不确定度传递算法;最后给出了宽带取样示波器带宽不确定度的评定结果.     

基于NTN技术的宽带取样示波器自动校准系统

与其它宽带取样示波器校准技术相比,NTN校准技术能够精确地获得取样示波器的冲激响应和复传递函数。但是,由于NTN校准技术要求两台取样示波器的输入端直接对接,这样就很难通过前面板对取样示波器进行操作。为此,介绍了一种基于NTN校准技术的宽带取样示波器自动校准系统,并详细介绍了系统的组成、功能及校准结果。该系统的整个校准工作是在PC机控制下完成的。     

86100A/B(DCA)宽带取样示波器原理、用途及校准方法

86100A/B取样示波器是一种宽频带、多功能的电子测量仪器.本文简叙了该仪器特有的功能、测量原理以及校准方法.由于高达50GHz的频带宽度,用经典的标准脉冲法已无法进行校准(即无法量值溯源),文中介绍了用NTN校准技术的新方法,进行50GHz取样示波器的上升时间、频带宽度的测量.     

86100A/B(DCA)宽带取样示波器原理、用途及校准方法

86100A/B取样示波器是一种宽频带、多功能的电子测量仪器。本文简叙了该仪器特有的功能、测量原理以及校准方法。由于高达50GHz的频带宽度,用经典的标准脉冲法已无法进行校准(即无法量值溯源),文中介绍了用NTN校准技术的新方法,进行50GHz取样示波器的上升时间、频带宽度的测量。     

基于NTN技术的宽带取样示波器过渡时间不确定度的研究

NTN技术是一种校准宽带取样示波器的新方法，NTN技术提供的测量量是kick—out脉冲响应（显示）波形数据，而宽带取样示波器的过渡时间是对kick—out脉冲响应波形数据进行反卷积分离等处理才能获得的导出量。提出了一种基于NTN技术的宽带取样示波器过渡时间的不确定度的全面评定方法。首先分析了NTN技术引入不确定度的主要因素，给出了不确定度计算公式；然后结合数据处理过程推导出不确定度的传递算法；最后给出了宽带取样示波器过渡时间不确定度的评定结果。     

Nose-to-Nose校准技术的仿真研究

Nose-to-nose校准技术可以对任意带宽的取样示波器进行自校准．早期的研究工作集中在对关键信号hick-out脉冲的仿真．本文从不同的角度对微波二极管取样头电路进行了全面的仿真,得到了结论：hick-out脉冲是由于在取样电路的不平衡时选通脉冲的泄漏造成的．并对NTN校准技术从仿真实验到物理实验做了介绍．     

带有连接电缆的"NTN"校准技术

在利用“NTN”校准技术对取样示波器进行校准时，为保证校准精度，要求两台取样示波器的输入端直接对接。但在实际运用中，为方便起见，常常将两台取样示波器的输入端用电缆连接在一起。显然，电缆的接入。将对“kick-out”脉冲的响应波形产生影响，这就要求在数据处理中扣除电缆的影响。详细介绍了带有电缆的“NTN”校准技术的实验设置、数据预处理算法(包括去时基抖动处理、消除取样电路的非对称性的方法等)、“kick-out”脉冲的反卷积分离以及扣除电缆影响的算法。最后，给出取样示波器阶跃响应的波形并进行了评价。     

宽带接地共面波导的时域测量方法研究北大核心CSCD

宽带接地共面波导是校准示波器宽带探头的核心器件。为了准确测量示波器探头的带宽指标,获得宽带接地共面波导传输特性成为实现高精度校准的关键。运用时域自动网络分析仪的测量原理,基于飞秒激光激励皮秒电脉冲技术,采用二次测量法,构建了接地共面波导二次时域测量系统,通过两次测量的方式解算出宽带接地共面波导的冲激响应,从而得到频域带宽指标。以阵列通孔结构仿真设计接地共面波导,采用二次测量法测量加工样品,3 dB带宽达54.2 GHz,与仿真结果相比具有较好的一致性。定标后的宽带接地共面波导可以作为标准器件,用于示波器宽带探头的校准,其测量结果可有效溯源至脉冲波形参数国家基准。     

基于光脉冲源的脉冲标准法中的时基漂移去除

时基漂移是影响取样示波器在时域精密测量高速脉冲信号的关键因素,所以要尽可能设法去除。本文研究以示波器86100C取样模块86118为设备背景,首次利用互相关算法对实时采集的数据,进行了去除时基漂移的研究,并用反卷积技术实现了示波器的校准。研究结果表明,互相关算法去除时基漂移效果明显、优于其他算法,并在一定程度上提高了光脉冲法校准示波器的校准准确度。     

A fast-pulse oscilloscope calibration system

A system is described for calibrating high-bandwidth oscilloscopes using pulse signals. The fast-pulse oscilloscope calibration system (FPOCS) is to be used to determine the step response parameters for digitizing oscilloscopes having bandwidths of ~20 GHz. The system can provide measurement traceability to standards maintained at the U.S. National Institute of Standards and Technology (NIST). It comprises fast electrical step generation hardware, a personal computer (PC) and software, and a reference waveform, i.e., a data file containing an estimate of the step generator output signal. The reference waveform is produced by prior measurement by NIST of the step generator output signal (calibration step signal). When the FPOCS is in use, the calibration step signal is applied to the device under test, which is an oscilloscope sampling channel. The measured step waveform is corrected for timebase errors, then the reference waveform is deconvolved from it. The results are impulse, step, and frequency response estimates, and their associated parameters (e.g., transition duration, transition amplitude, -3 dB bandwidth) and uncertainties. The system and its components are described, and preliminary test results are presented     

取样示波器nose-to-nose校准技术中kick-out脉冲的研究

研究了nose-to-nose校准技术中关键信号kick-out脉冲产生的机理以及影响因素,并通过将两台Agilent86100系列的50GHz的取样示波器对接,获得了kick-out脉冲的响应波形.     

Broadband sampling oscilloscope characterization with the“Nose-to-Nose” calibration procedure: a theoretical andpractical analysis

In the past the “nose-to-nose” calibration procedure has been introduced as probably the most accurate method to determine the impulse response of broadband sampling oscilloscopes like the HP54124T. The method is based on the hypothesis “sampler kick-out equals oscilloscope impulse response”. This hypothesis was originally based on an intuitive approach and was later verified experimentally (comparison with power measurements) as well as with SPICE simulations. Until now, however, there was no generalized mathematical evidence supporting this basic hypothesis. In this paper a mathematical theory is developed, which starts from a generalized sampler equivalent scheme, and which shows that, under conditions which are valid in practice, the sampler kick-out indeed equals the sampler impulse response. Experimental results are reported concerning the accuracy and precision of the calibration procedure. These experiments involve the investigation of experiment repeatability, noise, sampler linearity and timebase effects     

Quantifying the maximum phase-distortion error introduced by signalsamplers

Quantifying the errors introduced by signal sampler imperfections is of interest to people who are doing frequency domain measurements. The phase-distortion introduced by the sampler is hard to quantify and is usually neglected. In this article, upper bounds for this phase-distortion error are derived which are based upon simple assumptions, namely that the sampler weighting function is strictly positive, that it is limited in time, and that the function has only one local maximum. The theoretical limits are applied in order to specify the accuracy of a calibration procedure for broadband sampling oscilloscopes     

Traceable Waveform Calibration With a Covariance-Based Uncertainty Analysis

We describe a method for calibrating the voltage that a step-like pulse generator produces at a load at every time point in the measured waveform. The calibration includes an equivalent-circuit model of the generator that can be used to determine how the generator behaves when it is connected to arbitrary loads. The generator is calibrated with an equivalent-time sampling oscilloscope and is traceable to fundamental physics via the electro-optic sampling system at the National Institute of Standards and Technology. The calibration includes a covariance-based uncertainty analysis that provides the uncertainty at each time in the waveform vector and the correlations between the uncertainties at the different times. From the calibrated waveform vector and its covariance matrix, we calculate pulse parameters and their uncertainties. We compare our method with a more traditional parameter-based uncertainty analysis.     

Uniform sampling of periodic signals using successive conversions

This paper presents a new approach to the generation of uniform sampling signals which is based on multiple signal conversions: from pulse to digital, then from digital to analog and afterwards from analog back to pulse. It is shown that a conventional analog-to-frequency converter is suitable to be used as a controllable pulse generator providing for equidistant sampling pulses the frequency of which is proportional to the sampled signal frequency. This paper describes two methods for designing fast response, jitter-free sampling-time generators allowing accurate, uniform sampling of periodic signals. The prototypes have been built and tested     

Double buffered wide-range frequency measurement method for digitaltachometers

A new frequency measurement system suitable for a wide range of microprocessor-based applications is presented. The procedure used to calculate the frequency is based on the original double-buffered method. This new method utilizes both pulse counting, and measurement of the fractional pulse period during the fixed sampling time. The sampling time can be chosen to provide high accuracy and high resolution over a wide range of frequencies. Therefore, it is specially applicable in digital tachometers     

基于时间延迟的移动目标模拟器的设计与实现

针对实验室环境下单光束脉冲激光测速仪校准问题,本文提出了一种移动目标模拟器的设计与实现方法,该方法基于时间延迟的高精度脉冲序列的产生原理。文中设计了特定的延时脉冲序列,通过软件编程,控制数据定时发生器作为硬件电路生成设备,完成了延时脉冲序列的存储分配和电路生成,实现了具有任意标准速度的通用移动目标模拟器,并构建了激光测速仪检定装置。实验结果表明装置具有较好的测量重复性。