A method for extracting parameters of piezoelectric monolithic wafer equivalent circuit model

Abstract

A method for extracting parameters of equivalent circuit model of a piezoelectric monolithic wafer includes such steps of fixing one end of piezoelectric monolithic wafer on vibration source, making the other end, keeping constant sinusoidal vibration acceleration amplitude a, sweeping frequency to obtain relationship curve between output voltage and vibration frequency of piezoelectric monolithicwafer under different load resistances RL; determining the short-circuit resonant frequency fsc, the open-circuit resonant frequency foc, the static capacitance Cmc, the mechanical quality factor Qoc, the mechanical quality factor QML, the maximum power value Popt, the open-circuit resonant voltage Voc ([omega] oc); and calculating the equivalent inductance Lm, the equivalent capacitance Cm, theequivalent resistance Rm, the equivalent input stress VF, the piezoelectric coupling coefficient A and the static capacitance Cmc. The invention can accurately describe the relationship between the output voltage characteristic of the piezoelectric monolithic wafer and the load, the ambient vibration frequency and the acceleration, and the electric measuring instrument required for measuring is low in cost.

Description

technical field [0001] The invention relates to the field of vibration environment energy collection technology and circuit design, and more specifically relates to a method for extracting parameters of a piezoelectric single-chip equivalent circuit model. Background technique [0002] Vibration energy harvesting devices can convert the vibration energy widely present in the environment into electrical energy. The energy conversion methods are divided into three types: electrostatic, electromagnetic and piezoelectric according to the different electromechanical conversion principles. The electrostatic type is realized by the capacity change of the variable capacitor due to vibration. The most attractive feature of this method is that it has IC compatibility, and it can be manufactured by silicon micro-processing technology and mass-produced. But in order to realize voltage constraint or charge constraint across the capacitor, independent power supply support is required. El...

AI Technical Summary

Problems solved by technology

Some existing circuit parameter extraction methods rely on measuring the vibration state of the piezoelectric single crystal to calculate and determine the parameters, and the required measuring instruments such as Doppler laser vibrometers are expensive

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