无源RC积分器频率响应特性分析  

Frequency Response Analysis of Passive RC Integrator

作　　者：卫兵[1] 傅贞[1] 王玉娟[1] 顾元朝[1] 马冰[1] 

机构地区：[1]四川绵阳中国工程物理研究院流体物理研究所,绵阳621900

出　　处：《高电压技术》2008年第1期53-56,77,共5页High Voltage Engineering

基　　金：国家自然科学基金(10635050)~~

摘　　要：为分析无源RC积分器的频率响应特性,给出了包含杂散参数的无源RC积分器等效电路,应用PSpice软件进行了模拟计算,指出了RC积分器与RC低通电路幅频响应分析方法的差别,并给出采用20lg(RCωAU)作为波特图纵轴的分析方法。结果表明:无源RC积分器的频率下限由时间常数RC决定,在RC≥4.1(1/ω)范围内,幅频响应偏差<3%;频率上限则受积分器的杂散参数影响,最主要的参数是积分电容的杂散电感以及积分电阻的分布电容。对于输出端连接高阻负载的积分器,采用多个小容量陶瓷电容并联作为积分电容,并采用几个电阻串联作为积分电阻是改善积分器高频响应的有效方法,但必须注意积分器输出端的匹配;对于输出端连接传输电缆的积分器,则应采取同轴型设计。In order to analyze frequency response of passive RC integrator, the equivalent circuit including the tiny parameters of integrator was calculated with the OrCAD/Pspice. The results show that the lower limit of frequency response is determined by time constant （=RC）. When RC is 4.1 times more than 1/ω, the error of amplitude-frequency response is less than 3 %. The higher limit is determined by dispersed parameters. The most influence come from tiny inductance from C and the dispersed capacitance from R of RC integrator. It is the proper way to improve characteristic of integrator that the capacitance is made up of some parallel elements, and the resistance is made up of some element in series. The coaxial structure is designed for integrator that is connected to signal cable of which impedance is 50 Ω. The difference between RC integrator and RC low-pass circuit was described in analysis of frequency response. When 201g （RCωA∪） is used for vertical ordinate of Bode plot, the diagonal line in Bode plot which uses 201g A∪ as vertical ordinate changes for level. It accords with custom of analysis and easy to ascertain bandwidth of RC integrator. Because RC integrator is apart of monitor, the bandwidth is not determined by , 3 dB but by permissible tolerated error of integrator.

关 键 词：脉冲 测量 无源 RC积分器 幅频响应 杂散参数 

分 类 号：TP321.2[自动化与计算机技术—计算机系统结构]