Low Distortion Noise Filter Realized with Average High and Low Peaks Method

• Main Authors: Lin-JunYi , 林峻誼
• Other Authors: Chang-RongSeng
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/7wh5fy

博士 === 國立中央大學 === 光電科學與工程學系 === 106 === In general, the low-pass filter has a cut-off frequency; it can remove the higher order harmonics of the actual signal, but when the frequency of the noise is below the harmonic frequency, the result of square wave will have in distortion of the low slew rate. The process of dampening noise also changes the original signal, which in turn affects the subsequent steps of data processing. However, based on the distribution characteristics of noise, this paper proposes a method to obtain the corresponding upper envelope and lower envelope by extracting the high and low peaks of the input signal, by taking the average of the upper envelope and the lower envelope to reduce the Gaussian noise The design of the fast response filter, there is no cutoff frequency; so the actual signal of the harmonics remain unchanged. And therefore it can immediately respond to changes in the input signal and retain the integrity of the actual signal. In addition, it has only a small phase delay. The rotation rate, phase delay and frequency response can be confirmed from the simulation results of Multisim 13.0. The filter mentioned in this paper can preserve the harmonic of the original signal and achieve the rotation rate of 6.34v⁄μs and phase shift almost zero. The physical test V_in：3Vpp Gaussian Noise, after the noise filter V_out：120mVpp. Noise can be suppressed to 4% of the original signal.