基于AD835的正弦波测幅  

Measurement of Sinusoidal Signal Amplitude Based on AD835

作　　者：谭洋 刘建鑫 赵仕良[1] TAN Yang;LIU Jianxin;ZHAO Shiliang(School of Physics and Electronic Engineering,Sichuan Normal University,Chengdu 610000,China)

机构地区：[1]四川师范大学物理与电子工程学院,成都610000

出　　处：《实验室研究与探索》2021年第9期57-60,共4页Research and Exploration In Laboratory

摘　　要：应用高速乘法器AD835将被测正弦信号进行自乘,将乘法器输出信号通过放大和窄带低通滤波,获得与正弦信号振幅平方相关的直流信号,将直流信号通过A/D采样,由A/D采样值逆向获得正弦信号的振幅。从原理上讲,该方法是将交流信号变成携带幅值信息的直流信号进行测量,属于间接测量法。相对于直接测量法,该方法测量的是直流,可大大降低对A/D速度的要求,减少系统的成本;系统中直流纹波电压较小,通过少量数据的平均值来描述直流,提高系统的效率;系统能够测量的正弦波频率范围是由高速乘法器AD835决定的,提高了测量的带宽。该方法是一种低成本、高效率和高带宽的正弦信号测幅方法,同时该方法还可以测量任意周期信号的功率。Based on the high-speed multiplier AD835,the measured sine signal is self-multiplied,and the output signal of the multiplier is passed through an amplifier and a narrow-band low-pass filter to obtain a DC signal related to the square of the amplitude of the sine signal.Finally,the DC signal is sampled by AD.The amplitude of the sinusoidal signal is obtained in the reverse direction from the AD sampled value.In principle,this method is to change the AC signal into a DC signal carrying amplitude information for measurement,which is an indirect measurement method.Compared with the direct measurement method,this method measures DC,which can greatly reduce the speed requirement of AD,thus reducing the cost of the system.In order to improve the efficiency of the system,the ripple voltage of DC in the system is small,and the DC is described by the average value of a few data.The frequency range of sine wave that the system can measure is decided by the high-speed multiplier AD835,so the bandwidth of measurement is improved.Therefore,this method is a low-cost,high-efficiency and high-bandwidth sine signal amplitude measurement method.At the same time,this method can also measure the power of any period signal.

关 键 词：乘法器 窄带低通滤波器 直流信号 正弦信号测幅 

分 类 号：TM933[电气工程—电力电子与电力传动]