Weak Signal Detection Based on Duffing Oscillator

The capability of conventional detection method such as power spectral density is limited while detecting periodic signals buried in the noise and deciding accurate frequency, the chaotic oscillator can increase the detection ability of weak periodic signals and improve frequency precision. In this paper, a new method based on duffing oscillator is proposed to detect weak signals. The chaos characteristic and detection principle for weak periodic signals of duffing equation are analyzed. This paper researched on the chaos property of duffing oscillator equation with Melnikov criteria. Through analyzing the intermittent chaos mechanism of Duffing oscillator, it was found that the system output is a intermittent chaotic signal when input frequency deviates the compulsory drive frequency slightly, and the deviation can be estimated by the statistic characteristic of output chaotic signal. Simulation results show that this method can detect weak signals with extremely low signal to noise ratio.