小波数字滤波器的设计及在tanδ测量中的应用

The design of wavelet digital filter and its application intanδ measuring

由于现场电磁干扰的影响,采用基于快速傅里叶变换(FFT)的谐波分析方法进行介损tanδ测量时,测量精度难以达到工程要求。本系统以Mallat快速算法为基础,利用小波分析的多分辩率特性设计了小波数字滤波器的算法。根据对小波基的数学特性的分析,选择了一种适用于信号去噪的最优小波基,并讨论了小波分析分解层数的确定。最后利用MATLAB工具进行软件仿真。

When measuring the dielectric loss factor tanδ, the measuring precision is not contented by using the harmonic analysis method based on FFT (Fast Fourier Transform) because of the electromagnetic interference. The system included a digital filter utilizing the multi resolution character of the wavelet analysis based on the Mallat method. A optimized base of wavelet is selected after the mathematical analysis and the decomposing number is also discussed. The simulation result is given in Matlab.