Patent attributes
According to an embodiment, an intrusion detection sensor includes a microwave sensor (120) that transmits microwaves toward a detection area, receives the microwaves reflected by an object present in the detection area, and outputs a reflected wave reception intensity signal according to the received intensity; a direction variable antenna device (110); a scanning measurement means (131) that provides an instruction to scan the transmission/reception direction to the direction variable antenna device (110) to determine a relationship with the output of the reflected wave reception intensity signal; a detection target object presence determination means (132) that determines whether or not a detection target object is present based on the determined relationship; and an alarm signal output control means (133) that outputs an alarm signal when it is determined that a detection target object is present.