【摘要】 结合理论方法研究和具体硬件的设计,提出一种基于铌酸锂单晶基片的三频点标准超声换能器,由单片机控制DDS芯片产生3种频率的正弦信号,经过高频运算放大器电路,对标准超声换能器激励输出标准超声功率,从而形成三频点标准超声功率源,可作为一种超声功率传递标准。三频点标准超声功率源实现了18.9 MHz高频超声波的输出。和英国NPL测量比对的结果显示,3个频率点上的超声功率值误差均不大于±5%,验证了三频点标准超声功率源输出数据的有效性。更多还原

【Abstract】 Combining theoretical method research and specific hardware design,a three-frequency standard ultrasonic transducer based on Li Nb O3 single crystal substrate is proposed. The DDS chip is controlled by a single-chip microcomputer to generate sinusoidal signals of three frequencies. After a high-frequency operational amplifier circuit,the standard ultrasonic transducer is excited to output standard ultrasonic power,thereby forming a three-frequency standard ultrasonic power source,which can be used as a standard for ultrasonic power transmission. The three-frequency standard ultrasonic power source realizes the output of 18. 9 MHz high-frequency ultrasonic waves. The results of comparison with the British NPL measurement show that the error of the ultrasonic power value at the three frequency points is not more than ± 5%,which verifies the validity of the data output by the three-frequency point standard ultrasonic power source.更多还原