【摘要】 针对超声PT(process tomography)成像所使用的压电传感器应与激励源阻抗匹配的要求,采用导纳圆方法,剖析了压电传感器振子的谐振频率特性。自制水声收、发两用压电传感器,并采用相位跟踪法,设计了传感器参数测量电路。参数测量结果表明:当传感器振子处于自由状态下,其谐振频率和反谐振频率较低;处于夹持状态下,传感器谐振频率和反谐振频率较高,反谐振等效电阻阻值明显增加,达到12 kΩ.更多还原

【Abstract】 Aimed at the impedance matching between a piezoelectric sensor and its drive source,the resonant characteristics of the piezoelectric sensor were analyzed.A circuit was designed with the method of phase tracking,to measure the parameters of the piezoelectric sensors for sending or receiving ultrasonic waves.The experimental results show that,in the free state,the resonance frequency and the anti-resonance frequency of the piezoelectric ceramic oscillator are lower;in the clamping condition,the ones of the piezoelectric sensor are higher,and,the equivalent anti-resonant resistance value of the sensor obviously increases,to 12 kΩ.更多还原