| 摘要 |
An intrusion detection device of the dual sensing type has a PIR sensor to generate a PIR signal. The device also has a microwave sensor for generating a microwave amplitude signal. The microwave amplitude signal is filtered to generate a microwave high frequency signal which is the high frequency portion of the microwave amplitude signal. These three signals: PIR signal, microwave amplitude signal, and microwave high frequency signals are amplified and are digitized and are processed to generate an event signal. The event signal is compared to an event threshold signal and an alarm is generated in the event the event signal exceeds the event threshold signal. The event threshold signal represents the threshold to distinguish between a human intruder and an animal intruder.
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