One embodiment of a field coverage configurable passive infrared radiation intrusion detection device comprises a plurality of passive infrared radiation sensors. The device also has an optical element for gathering infrared radiation from different portions of a field and for focusing said infrared radiation onto said plurality of passive infrared radiation sensors. An electrical activation/deactivation circuit receives the output of each passive infrared radiation sensor and selectively activates/deactivates one or more of the plurality of passive infrared radiation sensor outputs thereby configuring the portions of the field covered by the passive infrared intrusion detection device. In another embodiment of a field coverage configurable passive infrared radiation intrusion detection device, the height coverage of the device is adjustable in the field. The device comprises a passive infrared radiation sensor, and an optical element spaced apart from the passive infrared radiation sensor by a separation distance, for focusing infrared radiation from a field at a height distance from the optical element. The device further comprises means for changing the separation distance, thereby changing the height distance of the optical element from the field.