| 摘要 |
<p>PURPOSE: To make it possible to detect motion of a target object situated behind an obstacle, by processing a change and a velocity of change in a phase difference measured by comparing a reflected signal with a transmitted CW radar signal. CONSTITUTION: A motion detecting radar system 10 is disposed about 1 to 5 feet apart from a construction 20 such as a wall which shields a moving target object to be detected. A receiver 13 receives a reflected wave from all reflecting surfaces in a visual field of a CW antenna 12 and compares it with a transmitted CW radar signal by the use of a phase sensing mixer 21 of a CW receiver 11. At this time, if any movement occurs in the whole visual field of the antenna 12, a fixed phase relation of the received signal changes and a phase velocity of an output of the receiver 13 changes, and therefore a minute Dc change being amplified by a high-gain AC amplifier 25, motion of a target object being converted into a recognizable tone by a tone generator 28 which is transmitted, by a FM transmitter 14, to a remote FM receiver 16 for monitoring. The receiver 16 hardly makes any sound when a moving target object does not exist while it outputs a clear alarm sound when a moving object exists.</p> |
