Millimeter wave portal imaging system

• US 20060017605A1
• Filed: 08/30/2005
• Published: 01/26/2006
• Est. Priority Date: 08/12/2003
• Status: Active Grant

• Current Assignee: Trex Enterprises Corporation
• Original Assignee: Trex Enterprises Corporation
• Inventors: Lovberg, John A., Kolinko, Vladimir, Bible, Robert Jr.
• Granted Patent: US 7,385,549 B2
• Time in Patent Office: Days
• US Class Current: 342/22
• CPC Class Codes: G01K 7/226 using microstructures, e.g. silicon spreading resistance
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01V 8/005 operating with millimetre waves, e.g. measuring the black losey radiation
• CPC Class Codes: H01Q 19/062 for focusing
• CPC Class Codes: H01Q 19/13 the primary radiating source being a single radiating element, e.g. a dipole, a slot, a waveguide termination H01Q19/15 takes precedence

Abstract

A millimeter wave portal imaging system for the detection of concealed weapons, explosives and other contraband items. A preferred millimeter wave imaging system includes a number (such as 64) of millimeter wave detection units each including a frequency scanning antenna and associated electronics. The units are mounted in four posts (16 per post) of a portal structure. Each unit collects frequency dependent beams of millimeter wave radiation from a narrow one-dimensional field of view. The collected radiation from each unit is amplified at the collected frequencies and the amplified signals are separated into frequency dependent bins with a tapped-delay beam-former. These bins are then sampled to produce a one-dimensional image of the antenna field of view. A two dimensional image of a portion of a person passing through the portal is obtained by moving the person (or having the person move) across the field of view of each of the frequency scanning antennas. The images from the antennas can be monitored separately or data from the antennas can be combined with a computer processor to form images of the person.

Claims

1. A millimeter wave portal imaging system for the detection of concealed weapons, explosives and other contraband items, said system comprising:

A) a portal structure;

B) a plurality of millimeter wave detection units mounted in said portal structure, each unit comprising,

1) a frequency scanning antenna defining an antenna field of view,

2) at least one low-noise amplifier for amplifying millimeter wave radiation detected by said antenna to produce an amplified millimeter wave signal,

3) a tapped-delay beam-former for separating said amplified millimeter wave signal into frequency dependent bins,

C) a data processor means programmed to sample said frequency dependent bins of at least a plurality of said detection units and to produce one or more images of objects carried under clothing by persons passing through said portal structure.

2. The system as in claim 1 and further comprising at least one monitor for displaying said images.

3. The system as in claim 2 wherein said data processor means is further programmed to produce at least one image of bodies of said persons displaying, in said at least one image, said objects.

4. The system as in claim 1 wherein each of said plurality of detection units detect a one dimensional image of a portion of said persons in a narrow, approximately vertical focused field of view and two-dimensional sub images are obtained by movement of said person horizontally across said narrow focused field of view.

5. The system as in claim 1 wherein said portal structure comprises four posts in which the millimeter wave detector units are mounted.

6. The system as in claim 1 wherein said millimeter wave detector units are configured to scan in a frequency range comprising the range of about 75.5 to 93.5 GHz.

7. The system as in claim 1 wherein each of said millimeter wave detector units comprise a cylindrical reflector system.

8. The system as in claim 1 wherein each of said millimeter wave detector units comprise a cylindrical Cassegrain-type reflector system.

9. The system as in claim 1 and further comprising a nuclear quadrupole resonance detector.

10. The system as in claim 1 and further comprising a metal detector.

11. The system as in claim 1 wherein each of said beamformers in each of said detector units comprises:

1) a plurality of delay lines,

2) a millimeter wave lens, and

3) a plurality of millimeter wave power detectors.

12. The system as in claim 1 wherein each of said low noise amplifier comprises three MMIC amplifiers fabricated on an indium phosphate substrate and a band pass filter.

13. The system as in claim 11 wherein said delay lines define copper surfaces having surface roughness less than 300 nanometers.

14. The system as in claim 1 and further comprising a sniffer system for detecting explosives.

15. A hybrid portal concealed weapon and contraband imaging and detection system comprising:

A) a portal metal detector, and

B) a portal contraband screener comprising a plurality of millimeter wave sensors, each of said plurality of millimeter wave sensors comprising;

1) at least one millimeter wave frequency scanning antenna for collecting frequency dependent beams of millimeter wave radiation from a narrow one-dimensional field of view;

2) a millimeter wave amplifier for amplifying at the collected frequencies said millimeter wave radiation;

3) a beam-former for separating said amplified collected radiation to produce frequency dependent signals corresponding to said frequency dependent beams, said beam-former comprising;

a) a plurality of delay lines,

b) a millimeter wave lens, and

c) a plurality of millimeter wave power detectors; and

4) a sampling circuit for reading out frequency dependent signals to produce a one-dimensional image of the antenna field of view.

16. A hybrid portal concealed weapon and contraband imaging and detection system comprising:

A) a nuclear quadrupole resonance detector, and

B) a portal contraband screener comprising a plurality of millimeter wave sensors, each of said plurality of millimeter wave sensors comprising;

1) at least one millimeter wave frequency scanning antenna for collecting frequency dependent beams of millimeter wave radiation from a narrow one-dimensional field of view;

2) a fast switch for calibration;

3) a millimeter wave amplifier for amplifying at the collected frequencies said millimeter wave radiation, said amplifier comprising at least three MMIC amplifiers fabricated on an indium phosphate substrate and a band pass filter;

4) a beam-former for separating said amplified collected radiation to produce frequency dependent signals corresponding to said frequency dependent beams, said beam-former comprising;

a) a plurality of delay lines,

b) a millimeter wave lens, and

c) a plurality of millimeter wave power detectors; and

5) a sampling circuit for reading out frequency dependent signals to produce a one-dimensional image of the antenna field of view, and

6) focusing means for focusing the sensor.