可调频率压电换能器原理
PRINCIPLE OF PIEZOELECTRIC FREQUENCY-TUNABLE TRANSDUCER
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摘要: 最近,我们曾研究电负载对压电振动系统振动特性的影响1,2。随着电负载的连续变化,通过压电效应,压电振动系统的谐振频率也连续地改变。由此引伸,可以实现可调频率压电换能器,本文将对其原理进行研讨。
我们将对压电夹心换能器进行这种调节频率的理论分析,并对一种纵向加电场,纵向振动的夹心换能器进行实验比较。理论与实验结果一致表明,用有效耦合系数Keff来衡量,该换能器可以在一个半倍频程的范围内有效地工作。
这里提出的可调频率压电换能器,由于是改变电负载,通过压电耦合来实现换能器的频率调节的,因此它还具有方便、连续和瞬时可调的特点。Abstract: Eecently, in our papers1,2 the effect of electric load on the characteristics of piezoelectric vibration system has been obtained. The resonant frequency of such a system changes continually with the changing of the electric load. In accordance with this effect, we made piezoelectric frequency-tunable transducers. In this paper, the principle of this freqency-tunable piezoelectric transducer is described.
We theoretically analyse the piezoelectric frequency-tuning of the sandwich transducers and experimentally investigate a sandwich transducer of length-vibration bar with field parallel to length. The theoretical and experimental results show that such frequency-tuning is available at one and half octaves.