宽波段低虚警率激光告警电路研究

为满足复杂电磁环境下的使用要求,克服强背景光干扰造成的高虚警率,设计了一种具有较强的抗电磁干扰能力和低虚警率的激光告警电路。分析了现有各种激光探测技术的特点和不足,有针对性的采用了模拟电路和数字电路相结合的方式,在模拟电路部分实现了探测激光波段的改进,在数字电路部分实现了虚警率的降低。范围采用灵敏度高、响应带宽宽的光电探测器作为来袭激光接收装置,可探测探测器响应频带内不同波段的来袭激光信号。基于可编程逻辑控制器件(CPLD)的逻辑驱动控制电路能按程序给定的规则判别来袭激光信号的脉冲宽度,排除干扰光信号造成的误判,降低虚警率。测试结果表明,该电路的放大电路增益G=30,信噪比为20dB,探测距离≤5km,探测波长范围为850～1 700nm,虚警率≤5%。

Study on Laser Warming Circuit with Wide band and Low False Alarm Rate

To meet the requirements of complex electromagnetic environment,and overcome the high false alarm rate caused by strong background light interference,a laser warming circuit was designed which had strong feature in anti-electromagnetic interference and low power consumption.The characteristics and the insufficiency of various existing technologies of laser detection were analyzed.Combined the analog circuit and digital circuit together,the detectable incoming laser wavelength was extended in the analog circuit part,achieving the improvements that the false alarm rates was lower than before according to the digital circuit part based on CPLD.Using high sensitivity and wide-band photo detector as the incoming laser receiver could detect different wavelengths of incoming laser signal in the response band of the photo detector.Logic drive circuit based on CPLD could distinguish the pulse width of the incoming light under the rules according to the procedures to eliminate false decision caused by other optical signal and reduce false alarm rate as a result.Testing results in practice showed that the circuit could achieve the targets as follow: amplifier gain G=30,SNR=20 dB,detection range≤5 km,detection wavelength range: 850~1 700 nm,the false alarm rate≤5%.