For anti-jamming and anti-countermeasure techniques of the sonar receiver, the response characteristics of the automatic gain control （AGC） circuit and the survivability of the prime circuit under strong interferenc...For anti-jamming and anti-countermeasure techniques of the sonar receiver, the response characteristics of the automatic gain control （AGC） circuit and the survivability of the prime circuit under strong interference are analyzed by simulations and experiments. An AGC simulation model based on the voltage control amplifier VCA810 prototype is proposed. Then static and dynamic simulations are realized with single frequency signal and linear frequency modulated （LFM） signal commonly used in the active sonar. Based on intense sound pulse （ISP） interference experiments, the real-time response characteristics of each module of the receiver are studied to verify the correctness of the model as well as the simulation results. Simulation and experiment results show that, under 252 dB/20 μs ISP interference, the specific sonar receiver will produce sustained cut top oscillation above 30 ms, which may affect the receiver and block the regular sonar signal.展开更多
The output amplitude of the differential circuit is studied for differential discrimination in pulsed laser time-offlight systems. Based on the studies of the probability of detection and the probability of false alar...The output amplitude of the differential circuit is studied for differential discrimination in pulsed laser time-offlight systems. Based on the studies of the probability of detection and the probability of false alarms, the minimum detectable input signal of differential discrimination can be calculated. The results indicate that the differential discrimination detectability of the small signal will be reduced. A combined discrimination is proposed in this Letter to improve the time resolution of the large signal and ensure the probability of detection of the small signal at the same time. A proper value of the circuit parameter is found to balance the time resolutions of the small and large signals.展开更多
基金supported by the National Natural Science Foundation of China (10974154)the National Innovation Project of China for Undergraduates (101069935)
文摘For anti-jamming and anti-countermeasure techniques of the sonar receiver, the response characteristics of the automatic gain control （AGC） circuit and the survivability of the prime circuit under strong interference are analyzed by simulations and experiments. An AGC simulation model based on the voltage control amplifier VCA810 prototype is proposed. Then static and dynamic simulations are realized with single frequency signal and linear frequency modulated （LFM） signal commonly used in the active sonar. Based on intense sound pulse （ISP） interference experiments, the real-time response characteristics of each module of the receiver are studied to verify the correctness of the model as well as the simulation results. Simulation and experiment results show that, under 252 dB/20 μs ISP interference, the specific sonar receiver will produce sustained cut top oscillation above 30 ms, which may affect the receiver and block the regular sonar signal.
文摘The output amplitude of the differential circuit is studied for differential discrimination in pulsed laser time-offlight systems. Based on the studies of the probability of detection and the probability of false alarms, the minimum detectable input signal of differential discrimination can be calculated. The results indicate that the differential discrimination detectability of the small signal will be reduced. A combined discrimination is proposed in this Letter to improve the time resolution of the large signal and ensure the probability of detection of the small signal at the same time. A proper value of the circuit parameter is found to balance the time resolutions of the small and large signals.
