The echo signal received by laser fuze was very weak when the detection range increased. In order to expand the operating range of fuze, the reception capacity of fuze for weak signal should be improved. According to the requirements of long-range laser fuze receiving system as small volume, low-power, low-noise, high-gain, the amplifying circuit of the receiving system was analyzed and designed. To improve the ability of laser fuze for detecting weak signal, the high-sensitive, low-noise, inner-gain avalanche photodiode (APD) was used as a photodetector in the system, and the low-noise preamplifier and voltage amplifying circuit was designed. The noise and frequency response of the amplifying circuit was researched and analyzed by simulation and experiment. The results show that the design is effective and feasible, which can meet the requirements of processing circuit as receiving weak signal from long-distance.
A 5.7GHz low noise figure ultra high gain CMOS LNA with inter stage technique
