一种MEMS谐振式传感器谐振频率与Q值的时频域测量方法OA

In order to ensure the sensitivity and stability of MEMS(micro electro mechanical systems)resonant sensors,the frequency and Q value must be measured precisely and effectively.Based on FPGA,an information processing method incorporating fast fourier transform(FFT),linear frequency modulation Z-transform(CZT),and Hilbert transform(Hilbert)is proposed.Firstly,the resonance frequency is obtained by analyzing the residual vibration signal of the resonator with a high-accuracy spectrum through the FFT and CZT transforms.Then,the Hilbert transform is performed on the aftershock signal to obtain the envelope.Finally,the envelope is fitted by using the least squares method to obtain the attenuation coefficient to further derive the Q value.The test results show that the method can accurately obtain the resonance frequency and Q value.The relative error of the resonant frequency reaches the order of 10-4.The relative error of the Q value reaches the order of 10-3,which is higher than that of the conventional spectrum analysis method.The method significantly reduces the measurement time compared to the sweep method.The research results have good references significance for the in-situ measurement of MEMS resonant sensors.