System and method for security inspection using microwave imaging

• US 8,681,035 B2
• Filed: 06/08/2005
• Issued: 03/25/2014
• Est. Priority Date: 11/24/2004
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Baharav, Izhak, Taber, Robert C., Lee, Gregory S., Kofol, John Stephen
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US11/148,079
• Publication Number:
  US 20060109160A1
• Time in Patent Office: 3,212 Days
• Field of Search: 340/540, 340/541, 340/552, 340/568.1, 342/22, 342 25 R- 25 F, 342/27, 342/28, 342/59, 342 82-103, 342/175, 342/176, 342/179, 342188-197, 342368-377
• US Class Current: 342/22
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01V 8/005 operating with millimetre waves, e.g. measuring the black losey radiation
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays

Abstract

A microwave imaging system uses microwave radiation provided by a microwave source to image targets. The system includes an array of antenna elements that are capable of being programmed with a respective direction coefficient to direct the microwave illumination from the microwave source toward a position on the target. The antenna elements are further capable of being programmed to receive reflected microwave illumination reflected from the position on the target. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the target. Multiple beams can be directed towards the target to obtain corresponding pixel values for use by the processor in constructing the image.

Claims

1. A microwave imaging system, comprising:

a microwave source for providing microwave illumination;

an antenna array including a plurality of antenna elements, each of said antenna elements operable to be programmed with a respective reflection coefficient to direct said microwave illumination towards a position on a target, said antenna elements being further operable to be programmed to receive reflected microwave illumination reflected from said position on said target; and

a processor operable to measure an intensity of said reflected microwave illumination to determine a value of a pixel within an image of said target constructed by said processor.

2. The system of claim 1, wherein said microwave source is configured to blanket illuminate said target with said microwave illumination.

3. The system of claim 2, wherein said antenna array is configured to receive said reflected microwave illumination reflected from said position on the target and direct said reflected microwave illumination towards a microwave receiver based on said respective direction coefficient associated with each of said antenna elements.

4. The system of claim 1, wherein said antenna array is configured to receive said microwave illumination from said microwave source and direct said microwave illumination towards said position on the target based on said respective direction coefficient associated with each of said antenna elements.

5. The system of claim 4, further comprising:

a microwave receiver operable to blanket receive said reflected microwave illumination reflected from said position on said target.

6. The system of claim 1, wherein each said reflection coefficient represents a phase state of said respective antenna element.

7. The system of claim 1, wherein each said reflection coefficient represents an amplitude state of said respective antenna element.

8. A method for microwave imaging of a target, comprising:

providing an antenna array including a plurality of antenna elements, each of said antenna elements operable to be programmed with a respective reflection coefficient;

receiving microwave illumination at said antenna array from a microwave source;

directing said microwave illumination towards a position on said target based on said respective direction coefficient associated with each of said antenna elements;

receiving reflected microwave illumination reflected from said position on said target;

measuring an intensity of said reflected microwave illumination to determine a pixel; and

constructing an image including multiple pixel values associated with multiple positions on said target.

9. The method of claim 8, wherein said receiving said reflected microwave illumination further includes:

blanket receiving said reflected microwave illumination reflected from said position on said target at a microwave receiver.

10. The method of claim 8, wherein said receiving said reflected microwave illumination further comprises:

receiving reflected microwave illumination reflected from said position on said target at said antenna array; and

directing said reflected microwave illumination reflected from said position on said target towards a microwave receiver based on a respective additional direction coefficient associated with each of said antenna elements.

11. The method of claim 8, wherein each said reflection coefficient represents a phase state of said respective antenna element.

12. The method of claim 8, wherein each said reflection coefficient represents an amplitude state of said respective antenna element.

13. A method for microwave imaging of a target, comprising:

providing an antenna array including a plurality of antenna elements, each of said antenna elements operable to be programmed with a respective reflection coefficient;

illuminating a position on said target with microwave illumination from a microwave source;

receiving reflected microwave illumination reflected from said position on said target at said antenna array;

directing said reflected microwave illumination reflected from said position on said target towards a microwave receiver based on said respective direction coefficient associated with each of said antenna elements;

measuring an intensity of said reflected microwave illumination to determine a pixel; and

constructing an image including multiple pixel values associated with multiple positions on said target.

14. The method of claim 13, wherein said illuminating further includes:

blanket illuminating said target with said microwave illumination.

15. The method of claim 13, wherein said illuminating further comprises:

receiving said microwave illumination from said microwave source at said antenna array; and

directing said microwave illumination towards said position on the target based on a respective additional direction coefficient associated with each of said antenna elements.

16. The method of claim 13, wherein each said reflection coefficient represents a phase state of said respective antenna element.

17. The method of claim 13, wherein each said reflection coefficient represents an amplitude state of said respective antenna element.

18. A microwave imaging system, comprising:

a microwave source for providing microwave illumination;

an antenna array including a plurality of antenna elements, each of said antenna elements operable to be programmed with a respective reflection coefficient to direct said microwave illumination towards a position on a target, said antenna elements being further operable to be programmed to receive reflected microwave illumination reflected from said position on said target; and

a processor operable to measure an amplitude of said reflected microwave illumination to determine a value of a pixel within an image of said target constructed by said processor.

19. A microwave imaging system, comprising:

a microwave source for providing microwave illumination;

an antenna array including a plurality of antenna elements, each of said antenna elements operable to be programmed with a respective reflection coefficient to direct said microwave illumination towards a position on a target, said antenna elements being further operable to be programmed to receive reflected microwave illumination reflected from said position on said target; and

a processor operable to measure a phase of said reflected microwave illumination to determine a value of a pixel within an image of said target constructed by said processor.

20. A method for microwave imaging of a target, comprising:

providing an antenna array including a plurality of antenna elements, each of said antenna elements operable to be programmed with a respective reflection coefficient;

receiving microwave illumination at said antenna array from a microwave source;

directing said microwave illumination towards a position on said target based on said respective direction coefficient associated with each of said antenna elements;

receiving reflected microwave illumination reflected from said position on said target;

measuring an amplitude of said reflected microwave illumination to determine a value of a pixel; and

constructing an image including multiple pixel values associated with multiple positions on said target.

21. A method for microwave imaging of a target, comprising:

providing an antenna array including a plurality of antenna elements, each of said antenna elements operable to be programmed with a respective reflection coefficient;

receiving microwave illumination at said antenna array from a microwave source;

directing said microwave illumination towards a position on said target based on said respective direction coefficient associated with each of said antenna elements;

receiving reflected microwave illumination reflected from said position on said target;

measuring a phase of said reflected microwave illumination to determine a value of a pixel; and

constructing an image including multiple pixel values associated with multiple positions on said target.