Reduction of 1/f noise in semiconductor devices based on wavelet transform and Wiener filter
基于小波变换和维纳滤波的半导体器件1/f噪声滤波

In order to reduce universal 1/f noise in semiconductor devices, a method with combining lifting wavelet transform and Wiener filter is presented. Firstly, the iteratively reweighted least square method is introduced to fit the power spectrum of 1/f noise and estimate its parameter, and then an appropriate wavelet can be selected. Secondly, the signal with 1/f noise is decomposed by lifting wavelet transform. Considering the fact that the wavelet transform whitens 1/f noise, Wiener filter is used to treat the wavelet coefficient of each layer. Allpass filter is optimized to adjust the phase frequency response of Wiener filter, and the phase of filtered wavelet coefficient is not changed. Finally, the useful signal embedded in 1/f noise is retrieved by the inverse lifting wavelet transform. Experimental study demonstrates the proposed procedure and verifies its effectiveness, and the experimental data are acquired from a force sensor developed for minimally invasive surgery robot. The results show that the method works very well in minimizing 1/f noise, and so the resolution of the sensor increases 25%.