Ultra Wide Band Detectors

Abstract

An ultra-wide band microwave based personnel/passenger screening system, and in particular, a system for material specific detection, uses non-ionizing radiation in which focused beams of low intensity microwave radiation are projected in rapid succession at an individual as they walk through a portal.

We claim: 
     
         1 . A portal for scanning a passenger walking through an inspection region along a longitudinal axis, wherein the passenger is carrying at least one object on the passenger's body, the portal comprising:
 a funneled entrance comprising a first set of two opposing panels installed at a first angle to the longitudinal axis, said first angle being in a range of 5 to 85 degrees;   a funneled exit comprising a second set of two opposing panels installed at a second angle to the longitudinal axis, said second angle being in a range of 5 to 85 degrees;   a central portal comprising a third set of two opposing panels positioned parallel to each other and located between said funneled entrance and funneled exit, wherein the first, second and third sets of two opposing panels form the inspection region and comprise a plurality of transmitter elements to project microwave beams on the passenger as said passenger passes through the portal and a plurality of receiver elements to receive scattered microwave beams from the passenger, and wherein more than one transmitter element is active simultaneously and generates a plurality of scans of the inspection region while the passenger passes through the portal; and   a plurality of processing blocks associated with said plurality of transmitter and receiver elements to process the scattered microwave beams and output data comprising at least one of a time, phase or frequency domain information, wherein the scattered microwave beams are a result of interactions of the projected microwave beams with an upper surface of the at least one object, a rear surface of the at least one object, and a portion of the passenger adjacent to the upper surface of the at least one object, and wherein said at least one of time, phase or frequency domain information is used to determine a location, shape, size or relative permittivity of the at least one object.   
     
     
         2 . The portal of  claim 1 , wherein the first and second sets of two opposing panels are installed at a first and a second angle to the longitudinal axis, said first and second angles being in a range of 20 to 60 degrees. 
     
     
         3 . The portal of  claim 1 , wherein each panel of said first, second and third sets of two opposing panels is approximately 2 m tall and has a width ranging between 0.4 m and 1.0 m. 
     
     
         4 . The portal of  claim 1 , wherein the first, second and third sets of two opposing panels are configured to scan a front surface, a rear surface and a plurality of side surfaces of the passenger. 
     
     
         5 . The portal of  claim 1 , wherein said plurality of scans are generated at a rate ranging between 5 and 100 frames per second. 
     
     
         6 . The portal of  claim 1 , wherein said microwave beams have frequencies ranging between 2 GHz and 20 GHz. 
     
     
         7 . The portal of  claim 1 , wherein an antenna coupled to each of said plurality of transmitter and receiver elements has a diameter ranging between 1 cm and 10 cm. 
     
     
         8 . The portal of  claim 1 , wherein said plurality of transmitter elements are activated in a sequential raster scan pattern. 
     
     
         9 . The portal of  claim 1 , wherein said plurality of transmitter elements are activated in a pseudo random scan pattern. 
     
     
         10 . The portal of  claim 1 , wherein said at least one object is displayed as an icon superimposed on a real-time video image of the passenger. 
     
     
         11 . The portal of  claim 10 , wherein said icon is colored to indicate a threat status of said at least one object. 
     
     
         12 . A method of scanning a passenger walking along a longitudinal axis of an inspection region of a portal, wherein the inspection region is defined by a central portal, an entrance funnel, and an exit funnel, wherein the central portal comprises a right panel and a left panel, said right and left panels opposing each other in a substantially parallel configuration, wherein the entrance funnel comprises a first panel positioned at an angle of 5 to 85 degrees relative to a front end of the right panel of the central portal and a second panel positioned at an angle of 5 to 85 degrees relative to a front end of the left panel of the central portal, and wherein the exit funnel comprises a first panel positioned at an angle of 5 to 85 degrees relative to a back end of the right panel of the central portal and a second panel positioned at an angle of 5 to 85 degrees relative to a back end of the left panel of the central portal, the method comprising:
 projecting RF beams on the passenger from a plurality of transmitter elements on each of the panels of said central portal, entrance and exit funnels, wherein more than one transmitter element is active simultaneously and generates a plurality of scans of the inspection region while the passenger transits through the portal;   receiving beams, scattered off the passenger, by a plurality of receiver elements on each of the panels of said central portal, entrance and exit funnels, wherein said scattered beams are a result of interactions of the projected RF beams with an upper surface and a rear surface of at least one object located on the passenger and with a surface on the passenger's body adjacent to the upper surface of the at least one object; and   processing the scattered beams, using a plurality of processing blocks associated with said plurality of transmitter and receiver elements, to output data comprising at least one of a time, phase or frequency domain information, wherein said at least one of time, phase or frequency domain information is used to determine a location, shape, size, or relative permittivity of the at least one object.   
     
     
         13 . The method of  claim 12 , wherein the angle of the first and second panels of each of said entrance and exit funnels ranges between 20 to 60 degrees. 
     
     
         14 . The method of  claim 12 , wherein each panel of said central portal, entrance funnel and exit funnel is approximately 2 m tall and has a width ranging between 0.4 m and 1.0 m. 
     
     
         15 . The method of  claim 12 , wherein the panels of said central portal, entrance funnel and exit funnel respectively scan a front surface, a rear surface and side surfaces of the passenger, substantially. 
     
     
         16 . The method of  claim 12 , wherein said plurality of scans are generated at a rate ranging between 5 and 100 frames per second. 
     
     
         17 . The method of  claim 12 , wherein said RF beams have frequencies ranging between 2 GHz and 20 GHz. 
     
     
         18 . The method of  claim 12 , wherein an antenna coupled to each of said plurality of transmitter and receiver elements has a diameter ranging between 1 cm and 10 cm. 
     
     
         19 . The method of  claim 12 , wherein said plurality of transmitter elements are activated in a sequential raster scan pattern. 
     
     
         20 . The method of  claim 12 , wherein said plurality of transmitter elements are activated in a pseudo random scan pattern.