The Design of Improved Duffing Chaotic Circuit Used for High-Frequency Weak Signal Detection

摘要

As the existing Duffing chaotic circuit is only fit for low frequency weak signal detection, this paper proposes an improved Duffing chaotic detection circuit, which overcomes the problem of instant saturation caused by high magnification and makes the Duffing chaotic circuit suitable for high-frequency weak signal detection. Adjusting the parameters of the circuit appropriately, the circuit can realize the weak signal detection ranged from low to high frequency. The performance of this circuit to detect high-frequency weak signal has been studied by simulation of Multisim. The simulation result shows that the circuit is very sensitive to the initial value. When a slight in crease in the amplitude of the sinusoidal signal, the phase transition from the chaotic state to the large-scale periodic state takes place at once, so it can be used to detect high-frequency weak signal. In addition, we find that the circuit is made up of two low-pass filters in series, the amplitude-frequency characte ristic curve of the circuit is obtained by simulation of Multisim,, and it verifies the performance that the circuit can also filter high-frequency noise.