TERAHERTZ SCREENING APPARATUS FOR DETECTION OF CONCEALED WEAPONS

• US 20150285907A1
• Filed: 05/05/2014
• Published: 10/08/2015
• Est. Priority Date: 05/03/2013
• Status: Abandoned Application

• Current Assignee: Farrokh Mohamadi
• Original Assignee: Farrokh Mohamadi
• Inventors: Mohamadi, Farrokh
• Application Number:
  US14/270,003
• Publication Number:
  US 20150285907A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• 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: G01S 7/026 involving the transmission of elliptically or circularly polarised waves
• CPC Class Codes: H01Q 21/0025 Modular arrays
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 5/25 Ultra-wideband [UWB] systems, e.g. multiple resonance systems; Pulse systems

Abstract

A system for screening, where a subject walks through a scanning area (for example, between two panels) provides readily deployable detectors for places where such detection may not normally be in use or available—such as public gatherings, voting lines, entrances of stadiums, religious gathering places, banks, and markets. High resolution imaging is achieved through implementation of central feed network elements, left-hand circularly polarized (LHCP) and right-hand circularly polarized (RHCP) arrays, and terahertz radar, as well as core signal processing at 5 GHz using ultra wideband (UWB) sensors. Terahertz technology provides screening of person borne improvised explosive devices (IED) including classification of explosive. A terahertz system provides high resolution RF imaging through deployment of a walk-in screener that can be unobtrusively or covertly installed.

Claims

1. A system comprising:

a plurality of radar transceivers disposed in an array, wherein;

the plurality of radar transceivers operate in a terahertz frequency band; and

the plurality of radar transceivers is configured to scan a subject within a walk-in scanning area;

a processor in communication with the plurality of radar transceivers, wherein the processor is configured to;

process image data from each of the plurality of radar transceivers;

combine the image data from the plurality of radar transceivers into a single image of the subject.

2. The system of claim 1, wherein one of the plurality of radar transceivers includes:

an antenna array comprising a plurality of antenna elements;

a feed network connecting an ultra wideband (UWB) signal to each of the antenna elements; and

a plurality of amplifiers dispersed in the feed network and configured to provide spatial power combining and beam forming of the UWB signal.

3. The system of claim 1, wherein:

a transmitter of the plurality of transceivers provides a range resolution in the range of 15 millimeters (mm) to 0.5 mm.

4. The system of claim 1, wherein:

a transceiver of the plurality of transceivers includes a 64×

64 element wafer scale antenna array measuring less than 20 mm per side.

5. The system of claim 1, wherein:

a transceiver of the plurality of transceivers includes a 64×

64 element wafer scale antenna array operating in the terahertz frequency band with a beam width of less than 1.0 degree.

6. A method for detecting concealed objects, comprising:

scanning a subject within a walk-in scanning area that places the subject within radar range of a plurality of radar transceivers operating in a terahertz frequency band;

processing image data from the plurality of radar transceivers;

combining the image data from the plurality of radar transceivers into a single image of the subject.

7. The method of claim 6, further comprising:

transmitting a radio frequency (RF) signal comprising an ultra wideband (UWB) pulse that is either a carrier-inclusive UWB-pulse or a carrier-less UWB-pulse;

receiving a reflection of the UWB pulse RF signal at the plurality of radar transceivers.

8. The method of claim 6, wherein:

operating in the terahertz frequency band provides a range resolution in the range of 15 millimeters (mm) to 0.5 mm.

9. The method of claim 6, wherein:

operating in the terahertz frequency band enables a transceiver of the plurality of transceivers to transmit with a beam width of less than 1.0 degree.

10. A walk-through scanning station comprising:

a modular array of radar transceivers including a plurality of scalable line cards, wherein each line card includes a radar transceiver configured to operate at V-band, W-band, or a terahertz frequency band;

a walk-in scanning area configured for a subject to pass within radar range of the modular array;

an image processor in communication with the modular array; and

a display in communication with the image processor for displaying an image of the subject scanned by the modular array of radar transceivers.

11. The scanning station of claim 10, wherein:

the image processor is in communication with a plurality of radar transceivers of the modular array;

wherein the image processor is configured to;

process image data from each of the plurality of radar transceivers; and

combine the image data from the plurality of radar transceivers into a single image of the subject.

12. The scanning station of claim 10, wherein the radar transceiver includes:

an antenna array comprising a plurality of antenna elements;

a feed network connecting an ultra wideband (UWB) signal to each of the antenna elements; and

a plurality of amplifiers dispersed in the feed network and configured to provide spatial power combining and beam forming of the UWB signal.

13. The scanning station of claim 10, wherein:

a transmitter of the radar transceiver provides a range resolution in the range of 15 millimeters (mm) to 0.5 mm.

14. The scanning station of claim 10, wherein:

the radar transceiver includes a 64×

64 element wafer scale antenna array measuring less than 20 mm per side.

15. The scanning station of claim 10, wherein:

the radar transceiver includes a 64×

64 element wafer scale antenna array operating in the terahertz frequency band with a beam width of less than 1.0 degree.