Patent ID: 8912944
Filing Date: 2014-12-16
Classification: G01S

Abstract:
1. A presence detector unit (PDU) of the type relying on microwave radiation, and providing a signal indicating movement within a defined space when such movement occurs, comprising: a) a housing having an interior space, at least a portion of which is made from material that blocks microwave radiation, and having a first side substantially transparent to microwave radiation; b) a source of microwave radiation within the housing and forming a beam of microwave radiation directed through the first side; c) a detector of changes in microwave radiation outside the housing; and d) an adjustable beam occlusion structure (ABOS) supported by the housing and blocking a portion of the microwave radiation emanating from the source and through the first side, and including at least one shutter movable within the microwave radiation beam, said shutter having a slot, and said shutter further including a fastener passing through the slot and attached to the housing.