| 摘要 |
A microwave motion-detection system incorporates apparatus for actively supervising the operability of the entire microwave system, from the transceiver component, through the output of its signal processing circuitry. Such supervision apparatus comprises a target simulator which responds to a time-varying electrical signal to cause the transceiver to respond as it does when detecting the type of change in reflected microwave energy normally caused by a target of interest moving in the region under surveillance. Preferably, such target simulator comprises a low-cost, general purpose diode positioned in close proximity to the receiver element of the transceiver, a low-frequency signal generator, and timing and control apparatus for periodically applying the output of the signal generator to such diode. In the event of a failure of any microwave system component during the target simulation operation, the supervision apparatus provides a "trouble" alarm. When the microwave system comprises one of the two components of a "dual-technology" motion-detection system, the timing and control apparatus assures a predetermined "quiet time" preceeding each target simulation operation. Such "quiet time" verifies that the microwave motion-detecting component is not continuously "in alarm", as may be caused, e.g., by a noisy receiver diode.
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