Active millimeter-wave imaging system

• US 20110102233A1
• Filed: 09/15/2008
• Published: 05/05/2011
• Est. Priority Date: 09/15/2008
• Status: Abandoned Application

• Current Assignee: Trex Enterprises Corporation
• Original Assignee: Trex Enterprises Corporation
• Inventors: JOHNSON, PAUL
• Application Number:
  US12/283,792
• Publication Number:
  US 20110102233A1
• Time in Patent Office: Days
• US Class Current: 342/22
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/325 using transmission of coded signals, e.g. P.S.K. signals
• 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

Abstract

An active millimeter wave imaging system and method. The system includes a spatially distributed broadband millimeter-wave illuminating source for illuminating a field of view and a millimeter-wave imaging receiver for imaging the field of view. The subject area to be imaged is illuminated simultaneously from many different angles by the distributed source. Reflections from the subjected area are then collected and used to form images. These images in preferred embodiments are compared with passive images made without the millimeter wave illumination from the millimeter wave source. The spatially distributed illumination source in preferred embodiments includes a broadband millimeter-wave noise generator producing millimeter wave radiation at frequencies at which the passive receiver is sensitive and a large reflector. In preferred embodiments the reflector has the shape of a section of an ellipse defining two foci.

Claims

1. An active millimeter-wave imaging system comprising:

A) an illumination source adapted to generate electromagnetic radiation at least one frequency range between 30 GHz and 300 GHz and to illuminate a field of view from a plurality of directions;

B) a millimeter wave imaging device adapted to collect millimeter wave radiation from a portion or all of the field of view and to produce millimeter wave images from the collected radiation.

2. The active millimeter-wave imaging system as in claim 1 wherein said illumination source 1 comprises a broadband noise generator.

3. The active millimeter-wave imaging system as in claim 1 wherein said illumination source 1 comprises a swept-frequency oscillator.

4. The active millimeter-wave imaging system as in claim 1 wherein the illuminating comprises an elliptical reflector antenna.

5. The active millimeter-wave imaging system as in claim 1 wherein the illuminating comprises an array of spatially distributed illumination sources.

6. A method of searching for contraband hidden beneath clothing of persons comprising the steps of:

A) providing an illumination source adapted to generate electromagnetic radiation at least one frequency range between 30 GHz and 300 GHz to illuminate a field of view from a plurality of directions;

B) providing a millimeter wave imaging device adapted to collect millimeter wave radiation from a portion or all of the field of view and to produce millimeter wave images from the collected radiation;

C) arranging for a person possibly carrying contraband under his clothing to stand in the field of view;

D) illuminating the person with the illumination source and produce images of the person and any hidden contraband with the imaging device.