| 摘要 |
<p>PURPOSE:To make the proximity fuse hard to find by an opponent side and to preclude malfunction by modulating a sent wave with a spread spectrum code and correlating the video amplifier output of a received signal with a code which is >=1 bits delayed behind the modulated signal. CONSTITUTION:The output of a code generator 10 is passed through a 1-bit delay circuit 11a to modulate a sent signal and send it. A reflected wave from a target is detected by a mixer 7 and correlated with by correlation detectors 13a, 13b, and 13c with a code which leads a received signal by 1 bit, a signal which is 1 bit delayed, and a code which is 1 bit plus DELTAT delayed behind the received signal. Then a threshold value corresponding to radio wave environment at the inside and outside of the proximity fuse is set for the output of the detector 13a through a bias adder 14. Then an igniting circuit 16 is operated through comparators 15a and 15b with the outputs of detectors 13b and 13c or the frequency is varied according the distance to the ground surface or sea surface through an integrator 17 and an attenuation quantity is varied. Consequently, sent power density per unit frequency band decreases, finding is made hard, and disturbance and malfunction are precluded.</p> |
