Nanosecond Miniature Transmitters for Pulsed Optical Radars

摘要

The-state-of-the-art in long-distance near-infrared optical radars is utilization the laser-diode-based miniature pulsed transmitters producing optical pulses of 3-10 ns in duration and peak power typically below 40 W. The bandwidth of the receiving channel nowadays exceeds 300 MHz, and thus the duration of the optical pulses exceeding 3 ns is a bottleneck in the task of high practical importance, namely increase in the radar ranging precision. Nowadays the speed of the high-current drivers is limited by the speed of a semiconductor switch that is typically field-effect transistor or an avalanche switch. The last one provides faster switching, and development of new avalanche switches is very challenging and important task, but this is not the only factor limiting the transmitter speed. Here we show that not only the switch, but also parasitic inductance in the miniature assembly and type of the capacitor play very important role in solving the problem of long-distance decimeter-precision radar.