基于LabVIEW的频率特性测试仪设计.doc.docVIP

基于LabVIEW的频率特性测试仪设计 摘 要 在电子测量中，信号频率方面的测试占很重要的地位。会经常遇到对网络的阻抗特性和传输特性进行测量的问题，其中传输特性包括增益特性、衰减特性、幅频特性、相频特性等。用来测量上述特性的仪器称为频率特性测试仪。本设计基于LabVIEW的频率特性测试仪就是完成对上述参量的检测。本文首先从系统所要实现的基本功能出发，介绍了总体方案及相应技术指标，论述了扫频测量的基本原理，包括系统动态特性的函数表征、系统动态特性测试方法、激励信号的产生与控制等。 本设计基于虚拟仪器思想和频率特性分析相关理论，提出了用虚拟仪器方式开发频率特性测试仪的新思路。设计的目标就是用美国国家仪器公司提供的虚拟仪器开发平台—LabVIEW，并结合相应的硬件环境，实现一个实用性较强的虚拟频率特性测试仪。 设计的频率特性测试仪包括三部分：（1）数据采集；（2）数据分析与处理；（3）存储、显示和打印。设计的内容从仿真和硬件两方面都调试通过。其中，硬件方面是通过搭建滤波电路作为外部系统实现的。 关键词：虚拟仪器，LeaBIEW，扫频测量，频率特性 DESIGN OF FREQUENCY CHARACTERISTIC TEST INSTRUMENT BASED ON LABVIEW ABSTRACT In electronic measurement, the frequency of measurement is a very important part. We will often encounter the network impedance characteristics and transmission characteristics of the measurement.The transmission characteristics include the gain and attenuation characteristics, amplitude and frequency characteristics of phase frequency characteristics. The apparatus used to measure the characteristics are known as the frequency characteristics of testing equipment. Here aim of the frequency characteristics test instrument we design based on LabVIEW is the completion of previous parametric testing. This paper firstly realizes the basic functions, then on the hardware platforms of construction. The software system design and implementation are paid attention in this paper. We discuss the basic principle of the sweep check, including the dynamic characteristics of the function characterization, the dynamic characteristics test methods, and excitation signal for the selection and control. Based on virtual machines defination and frequency analysis of the relevant theories, frequency characteristics test virtual instruments is introduced. The objective is to by use of LabVIEW the United States state equipment companies provide the platform for the development of virtual instruments, and combine with hardware environment, a strong frequency characteristic of virtual Instrument system is realized. Test frequency design can be