数字激光告警系统探测接收前端设计

Design of Detecting Receive Front-end for Digital Laser Warning System

探测接收前端是激光告警系统的关键部件,针对数字激光告警系统设计激光脉冲探测接收前端。采用宽带、高增益、低噪声的跨导放大方式实现了对最小来袭激光脉冲产生的10 nA,10 ns的微弱窄脉冲电流的放大,采用放大器饱和方式实现信号的整形,把来袭激光脉冲转换、放大成数字系统能处理的数字脉冲,脉冲宽度代表作用能量大小。前端最小可检测来袭激光信号能量达1μW,动态范围达100 dB。该宽带低噪声跨导放大电路很好地处理了电容对窄脉冲的影响,具有带宽宽(500 MHz),成本低的特点,为放大微弱的ns级及以下的窄脉冲电流信号提供一个很好的宽带方案。该设计结构简单、成本低廉、易于维护,不仅可用于激光来袭探测,还可用于激光安防系统等。

Detecting receive front- end is a key unit of laser warning system. In the design, a broadband, high gain, and low noise transimpedance amplifier to amplify the least pulse current 10nA, 10 ns by the incident laser is used, and a saturation of amplifier to regulate the large signal is employed, which transforms the raid laser signal into digital pulse. The digital pulse width shows the incident laser energy and can be processed by digital system. As a result,a 1 μW of the minimum raid laser energy can be detected,and 100 dB detecting dynamic range be got. The transimpedance broadband amplifier has been deal with the capacitors＇ behave to the narrowband current rightly, has a 500 MHz band,it＇s a good and less- cost example for amplifying ns level feeble current pulse. The design has characters of simple structure and easy maintenance, can be restructured in civil laser security system.