Weak signal detection performance of improved Duffing circuit
Zhihui Li · Dianji yu kongzhi xuebao · 2011
In order to solve the problem that the existing Duffing chaotic circuit applies only to low-frequency weak signal detection,an improved circuit designed using actual electronic devices is presented.Through adjusting the parameters of the circuit,it could detect weak signal from low frequency to high frequency.In addition,by the Multisim simulation of the circuit at higher frequencies,its detection performance was studied.Experiments show that the circuit is very sensitive to initial values,and it changes its state from the chaotic state to the large-scale periodic state when the sinusoidal signal amplitude increases slightly.By adding thermal noise,the detection ability of the circuit under noise background was analyzed,meanwhile the signal to noise ratio(SNR) was obtained.Results show that with the increase in the accuracy of the critical threshold,namely the increase in detection accuracy,the SNR becomes lower and lower.