Processing of Signals of Ring-Shaped Spots in Dielectric Barrier Discharge

Fast Fourier transform of the time series is an important way to analyze the periodic and chaos behavior of the signal. In this paper, the light signals of two types of ring-shaped spots, which are found in dielectric barrier discharge in the mixture of air and argon with two liquid electrodes, are recorded and compared through fast Fourier transform. It can be seen from the fast Fourier transform power spectra that, for the light signal of small ring-shaped spot, there still exists subharmonic frequency 1/2F and 1/4F, which is related to the periodic amplitude of the signal, besides the fundamental frequency F. However, for the large ring-shaped spot, the Fast Fourier transform power spectrum of light signal only has the basic frequency F, which reflects its temporal periodicity.