Low-frequency Sampling Method for High Frequency Periodical Signal

During the conversion from analog signal to digital signal,the sampling frequency is the key factor for conversion results.The setting of sampling frequency is limited by nyquist theorem,and the digitalized system for traditional analog signal can only process the analog signal with lower frequency.A method which is beyond the limitation of Nyquist theorem is derived and verified in this paper.In some systems where the analog signal is converted into digital signal,the lower sampling frequency can be used for the sampling of high frequency periodical signal through this method,and therefore the digital processing technology can be extensively employed.