论文部分内容阅读
针对双激励宽带换能器发射响应起伏较大的问题,本文提出了在前后压电陶瓷堆分别串联电阻来降低换能器工作频带内的发射电压响应起伏,拓展换能器工作频带的方法.推导了双激励换能器的等效电路,计算了在前后压电陶瓷堆分别串联不同电阻时换能器发射电压响应起伏随频率的变化关系,并通过有限元数值仿真证明,在前后压电陶瓷堆上串联合适的电阻,可以有效降低换能器发射电压响应在工作频带内的起伏.最后制作了工作频带在14~34 kHz的双激励超声换能器,测试了该换能器在串联不同电阻时的发射电压响应随频率的变化关系.实验测试结果表明在前后压电陶瓷堆串联电阻,可以有效地降低换能器的发射响应起伏,换能器在14~34 kHz的工作频带内发射电压响应的起伏由原来的12 dB降低到7.3 dB,换能器工作频带内的发射响应起伏得到明显的改善.研究结果对双激励宽带换能器的设计具有一定的意义.
In order to solve the problem that the response of the double-excitation wideband transducer fluctuates greatly, this paper proposes a method of reducing the voltage fluctuation in the working frequency band of the transducer and increasing the working frequency band of the transducer by connecting resistors in series respectively. The equivalent circuit of double excitation transducer is deduced. The relationship between the voltage fluctuation of the transducer and the fluctuation of the voltage of the transducer when the piezoelectric ceramic stack is connected in series with different resistance is calculated. The finite element numerical simulation shows that the piezoelectricity Ceramic heaps series resistor in series, can effectively reduce the emission voltage response of the transducer in the working frequency band of the ups and downs.Finally, the working frequency band 14 ~ 34 kHz double excitation ultrasonic transducer was tested the transducer in series The results show that the series resistance of the piezoelectric ceramic stack before and after can effectively reduce the emission response of the transducer. The transducer operates in the frequency range of 14 ~ 34 kHz The fluctuation of the emission voltage response is reduced from 12 dB to 7.3 dB, and the emission response fluctuation in the working frequency band of the transducer is obviously improved. Broadband transducer design has some significance.