共查询到19条相似文献,搜索用时 265 毫秒
1.
在无线电高精度测距系统中,对变频器进行准确的时延测量具有很重要的意义。对频率变换器件时延特性的把握无疑决定了测距的精度。阐述了时延的概念以及时延的测量方法,重点分析了基于矢量网络分析仪的2种测量方法。提出分析了一种基于时延测量设备,利用高速示波器进行准确的变频器时延测量方法,分析了该测量方法的性能。实践证明该方法切实可行,可以提高变频器时延测量的准确度。 相似文献
2.
3.
本文提出了一种四通道信号源相对时延的测量方法,基于通用数字存储示波器,能在测量四通道信号源相对时延的同时,获得示波器通道之间以及不同连接电缆之间的时延校正参数。该方法特别适合应用于输入不可见的多通道数模混合系统,可扩展适应任意数目的多通道信号源系统,无需使用任何标准测试件,弥补了网络分析仪测量时延的局限性,方便非专业用户使用。 相似文献
4.
网络分析仪的工作原理及在测量领域的应用 总被引:3,自引:0,他引:3
介绍了矢量网络分析仪的基本原理、应用范围,通过对矢量网络分析仪原理的介绍和误差修正,帮助理解和改进使用矢量网络分析仪进行测量的各种方法。同时详细介绍了矢量网络分析仪在部分测量领域的使用。包括:如何解决高功率放大器在测量中大功率电平的问题;如何解决电缆测量中延迟时间的问题;如何改进反射测量;如何利用频偏方式来测量混频器、变频器和调谐器等频率转换器件;如何提高非插入式器件测量的精度。 相似文献
5.
主要是介绍了网络分析仪的使用范围和运用原理,并且通过对网络分析仪运用原理的论述,将矢量网络分析仪在测量领域中的使用方法表述出来。与此同时,还将详细介绍矢量网络分析仪在测量领域中的作用,包括了:怎样解决电缆测量中延迟时间的问题;怎样解决高功率放大器在测量中大功率电平的问题;怎样利用频偏方式来测量变频器、调谐器和混频器等频率转换器;怎样提高非插入式器件测量的精度;怎样改进反射测量。 相似文献
6.
7.
在测距系统中,天线时延初值的测量是很重要的。首先简述了信标塔法和无塔标校法测量圆口径天线时延的原理和方法。提出了利用矢量网络分析仪测量天线时延初值的一种简单方法。实践证明:该方法简单易行,在实际工程测量中,值得推广和应用。 相似文献
8.
9.
10.
IP网络分组的时延是指从发送分组到接收分组之间的时间差。基于以下原因认为时延的测量对于IP网络的拥塞控制以及网络的服务质量都十分重要:首先,某些应用会因端到端时延过大而不能很好地执行,甚至不能执行;其次,时延不确定的变化使得网络对很多交互式实时应用的支持变得很困难;最后,时延值越大传输层协议对于高带宽应用的支持就越困难。网络运营商为了向用户提供优质的服务和对网络进行优化,需要了解IP网络的当前情况,则很有必要测量网络分组的时延。而且,IP网络性能中的其他一些指标的测量也是以时延测量为基础的,比如时延变化(有时候 相似文献
11.
提出了一种基于下变频的飞行时间-时间数字转换(TOF-TDC)原理的微波光子传输链路延时抖动测量技术,并详细地阐述了该技术的基本原理、系统构架以及参数设计等.该技术能以飞秒量级的测量精度以及大延时测量范围对信号延时抖动进行测量.环境因素导致的延时抖动严重地影响了高频模拟微波光传输相位传递,进而制约其在光控相控阵等领域中的广泛应用.所提出的延迟抖动测量技术从本质上解决了光传输链路在电子战、宽带雷达等宽带应用场合中稳相传输所遇到的一个基础性问题,具有很大的应用推广潜力. 相似文献
12.
Kun Jiang Yuanqin Wang Pingbo Yan Xiaomin Hou Hong Ma Yiwen Jiao 《Circuits, Systems, and Signal Processing》2014,33(11):3539-3553
The existing group delay measurement methods can only get the group delay at a certain aperture or frequency perturbation in one or two measurements. A new method based on comb signal is proposed. If modulo delay ambiguity can be ignored, then the method permits measurement without frequency perturbation of the test signal in one single measurement. The whole phase character of the test band can be obtained, and the group delay characteristics can be calculated by polynomial fitting of the phase curve at diverse aperture. A group delay ambiguity resolution method based on extended Chinese remainder theorem (CRT) is detailed. If modulo delay ambiguity cannot be ignored, then the extended CRT method can be used to obtain the unambiguity delay, releasing the operator from the constraint of keeping the aperture or frequency perturbation small. Computer simulations and field experiments are presented to verify the proposed methods. 相似文献
13.
14.
15.
The phase-shift method is an established technique for measuring the group delay of fiber-optic components. In devices, such as chirped fiber Bragg gratings, the group delay exhibits ripple as a function of wavelength. We have analyzed the dependence of the measured ripple amplitude on the modulation frequency and present a physical model, which gives an analytical formula for estimating the measurement error 相似文献
16.
The circuit configuration, operational principles, and some test data on three new types of equalizers applicable for use in FM microwave radio links are described. The equalizers are namely of the reflection type, frequency converter type, and AM-PM conversion type. The reflection type delay equalizer permits variation of relative delay time while keeping the absolute delay time constant at the center frequency or permits variation of absolute delay time while keeping the relative delay time constant. The frequency converter type equalizer adopts a principle whereby variation in local frequency (supplied to the frequency converter) facilitates continuous variation of the relative delay time, absolute delay time, and amplitude frequency response. The AM-PM conversion type differential gain equalizer enables equalization of differential gain through the combined use of the AM-PM converter circuit and the delay circuit. 相似文献
17.
Design of mechatronic systems with aliased plant modes 总被引:1,自引:0,他引:1
When digital components are combined with analog systems, frequency components in the analog system which are above one-half the sampling frequency are excited by the output of digital-to-analog (D/A) converters and aliased to lower frequencies in analog-to-digital (A/D) conversion. Since low-frequency components in a digital signal excite only higher frequencies during D/A conversion which are aliased to the same lower frequencies during A/D conversion, the D/A converter, analog plant, and A/D converter can be modeled by an aliased frequency response function (AFRF) which includes these aliased frequency effects. System identification using digital excitation and acquisition can identify the AFRF directly, or it can be developed from the frequency response function of the analog plant. Using this AFRF, controller design can proceed using conventional methods, and issues of stability, controllability of aliased modes, etc., are automatically taken into account in the design process 相似文献
18.
Maak P. Frigyes I. Jakab L. Habermayer I. Gyukics M. Richter P. 《Lightwave Technology, Journal of》2002,20(4):730-739
A true-time optical delay line for short radiofrequency (RF) pulses using path length dispersion is proposed. It is an optical implementation of the linear phase-shift theorem of the Fourier transformation. Acoustooptic signal processing is used for conversion into the optical frequency domain and for spatial Fourier decomposition of the pulse. The processing of the pulse is obtained by differentially phase shifting the particular frequency components, followed by a heterodyne reconversion into the RF domain. The optical system is intended to be used for delaying, but also for shaping and filtering of RF pulses, mainly in phased array radar antennas. Theoretical analysis of the system principle is given together with experimental results, demonstrating 2-μs time delay of 0.5-μs-long pulses with maximum optical phase shift of 1.2π. A detailed theoretical and experimental bandwidth analysis is carried out, pointing to the main technical problems and their solutions 相似文献