Analysis of Piezoelectric Acoustic Sensor Based on Negative Impedance with FEM in Composite Materials
Piezoelectric acoustic sensor with negative impedance matching circuit is put forward to enhance its sensitivity at low frequencies. The multi-physics problem coupled with sound wave equations, structure stress-strain equations, piezoelectric constitutive equations and electric ordinary equations is analyzed with FEM in detail. Frequency response characteristics are simulated when shunted with negative-capacitance, resistance in series. Sensitivity is obtained from 1kHz to 5kHz. When used proper electrical elements, the sensitivity of the piezoelectric sensor can even exceed that of no matching circuit over 2 factors in broad band.
Helen Zhang and David Jin
W. Q. Zhang et al., "Analysis of Piezoelectric Acoustic Sensor Based on Negative Impedance with FEM in Composite Materials", Advanced Materials Research, Vol. 321, pp. 109-112, 2011