Patent ID: 6950021
Filing Date: 2005-09-27
Classification: G01S,G08B

Abstract:
1. An apparatus for detection of any intruder passing through a protected volume, comprising: a first means for generating and modulating electromagnetic wave energy; a second means coupled to said first means for radiating said electromagnetic wave energy into said protected volume; a third means co-located with said second means for collecting a portion of said radiated electromagnetic energy; a fourth means for reflecting, said fourth means capable of redirecting a portion of said electromagnetic wave energy from said second means toward an associated fifth means for reflecting, said fifth means capable of redirecting said electromagnetic wave energy back along a same line of propagation to said fourth means and thus to said third means, thereby forming an electromagnetic beam comprising radiated and reflected electromagnetic wave energy and having two segments, a first segment between said fourth means and said fifth means, and a second segment between said fourth means and said third means; a plurality of said fourth means and a plurality of said fifth positioned along a base and ends of said protected volume for forming a plurality of said electromagnetic beams, each said electromagnetic beam comprising said first and second segments with a sum of lengths of said first and second segments being unique; a structure located at a proximal end of said protected volume and coupled to both said second means and said third means capable of supporting said second means and said third means at a position above said base of said protected volume for providing line-of-sight propagation of said electromagnetic beams between said second means and said third means and each of said plurality of said fourth means; said structure located at said proximal end of said protected volume also capable of being coupled to and supporting another set of said plurality of said fifth means, thereby providing a terminal end of said plurality of said electromagnetic beams at a plurality of heights above said base of said protected volume at said proximal end; a structure located at a distal end of said protected volume and coupled to and supporting another set of said plurality of said fourth means at a plurality of heights above said base of said protected volume, thereby providing junctions between said first and second segments of said plurality of said electromagnetic beams at said plurality of heights above said base of said protected volume at said distal end; a signal processing means coupled to said third means and capable of determining a range to objects irradiated by said radiated electromagnetic wave energy, said signal processing means monitors a presence of said electromagnetic beams associated with each said fourth means and associated said fifth means, and for detecting a physical presence of said intruder within said protected volume, and; an alarm circuit coupled to said signal processing means for generating an alarm when at least one of said electromagnetic beams is interrupted.