基于FPGA的电磁超声脉冲信号发生器的设计

Design of electromagnetic ultrasonic pulse signal generator based on FPGA

激励信号源是电磁超声检测系统的核心模块之一,其输出信号决定了电磁超声检测仪检测的质量。按照电磁超声检测系统对激励源的要求,设计了相应的正弦脉冲激励源。该设计系统主要包括FPGA的硬件语言合成脉冲信号、D/A转换、滤波放大、功率放大和阻抗匹配等硬件电路。该系统可输出频率、初始相位、占空比可调的脉冲正弦信号,满足EMAT对激励源的要求。可为设计便携式的电磁超声检测仪提供借鉴。

Excitation signal source is one of the core modules of the electromagnetic ultrasonic testing system,whose output signal determines the quality of the detection of electromagnetic ultrasonic detector. According to the requirement of the excitation source of the electromagnetic ultrasonic testing system, we have designed the sine pulse excitation source. The system mainly includes the FPGA hardware language to synthesize the pulse signal, digitial to analog convertion, filter and amplify, power amplifier, impedence matching and some other hardware circuit. The system can output the sin pluse signal whose frequence, initial phase and duty ratio can be adjusted and meet the requirment of EMAT. The project provides reference for the design of portable electromagnetic ultrasonic detector.