超声波传感器深度增益补偿电路设计  

Design of depth gain compensation circuit of ultrasonic transducer

作　　者：张永宏[1] 井晨志 王琦[1] 

机构地区：[1]南京信息工程大学信息与控制学院,江苏南京210044

出　　处：《传感器与微系统》2014年第2期123-126,共4页Transducer and Microsystem Technologies

基　　金：江苏省高校研究生科研创新计划资助项目(CXLX12-0516)

摘　　要：为了补偿超声探伤信号在动车组转向架中的传播损耗,利用超声波传感器,根据深度增益补偿的基本原理和微弱信号在不同深度处的衰减规律,设计了基于现场可编程门阵列(FPGA)的数字可控制式的增益放大补偿方法和电路。由XC6SLX16型FPGA的PLL模块产生精确的时钟控制信号,并输出数字量到DA芯片产生补偿电压曲线控制AD8330的放大增益倍数,再使深度补偿增益后的回波模拟信号进入LTC2249芯片内转换成数字信号,以便为下级数字信号再处理使用。实验结果表明:在超声波探伤仪系统的电路输入端加入频率为5 MHz、峰峰值为2 mV的正弦波激励后,通过改变步进值为5 dB的3种不同增益的大小,可以实现不同的放大增益,使衰减得到补偿。In order to compensate transmission attenuation of ultrasonic inspection signal in bogie of CRT,take advantage of ultrasonic wave transducer,according to theory of DGC and the attenuation law of week signal at different depth,the design is about the method and the circuit of FPGA-based digital controlling gain amplification compensation.Firstly,PLL module of FPGA in type XC6SLX16 produces exact clock control signal to control gain amplification magnitude of AD8330 by compensation voltage curve produced by output digital quantity to DA chip,then echo simulation signal is transmitted into LTC2249 chip and converted into digital signal,so that can be used in the reprocessing of the next level digital signal.Experimental results show that by adding sine wave whose frequency is 5 MHz and peak to peak value is 2 mV into the circuit input end of the ultrasonic fault detector system and altering the three different gain magnitudes of the 5 dB stepping to realize different amplification gains which can compensate attenuation.

关 键 词：超声波衰减 现场可编程门阵列 超声波传感器 深度增益补偿 

分 类 号：TN79[电子电信—电路与系统]