Composite dipole array

• US 20050200550A1
• Filed: 02/15/2005
• Published: 09/15/2005
• Est. Priority Date: 02/16/2004
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Holly, Sandor, Vetrovec, Jan
• Granted Patent: US 7,486,250 B2
• Time in Patent Office: Days
• US Class Current: 343/820
• CPC Class Codes: F41H 11/136 Magnetic, electromagnetic, acoustic or radiation systems, e.g. ground penetrating radars or metal-detectors
• CPC Class Codes: G01N 21/3581 using far infrared light; using Terahertz radiation
• CPC Class Codes: H01Q 21/00 Antenna arrays or systems arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system H01Q3/00
• CPC Class Codes: H01Q 21/062 using dipole aerials; H01Q21/067, H01Q21/068 take precedence
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them

Abstract

Methods and systems for generating and imaging THz electromagnetic radiation using a composite dipole array made up of novel structures of non-linear dipole strings with dual frequency resonances for frequency up conversion and frequency down conversion are disclosed. THz electromagnetic radiation resulting from the frequency down conversion process can be used as an illumination source for imaging, as a carrier for communications, or as an energy source for spectroscopy, for example. Optical electromagnetic radiation resulting from the frequency up conversion process can be used to form images from THz electromagnetic radiation for contraband detection, guidance systems, and medical applications, for example.

Claims

1. A linear dipole array comprising:

a plurality of dipoles defining a generally linear array; and

a non-linear resonant circuit electrically interconnecting adjacent dipoles.

2. A composite dipole array comprising:

a plurality of linear dipole arrays defining a generally planar array, each of the linear dipole arrays comprising;

a plurality of dipoles defining a generally linear array; and

a non-linear resonant circuit electrically interconnecting adjacent dipoles.

3. The composite dipole array of claim 2, wherein the individual dipoles are configured to be resonant at a frequency and the linear dipole arrays are configured to be resonant at another frequency.

4. The composite dipole array of claim 2, wherein the individual dipoles are configured to be resonant at an infrared frequency and the linear dipole arrays are configured to be resonant at a THz frequency.

5. The composite dipole array of claim 2, wherein the non-linear resonant circuits are configured to inhibit current flow between adjacent dipoles at one frequency more than they inhibit current flow between adjacent dipoles at another frequency.

6. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprises a diode.

7. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprises a diode and at least one of a capacitor and an inductor.

8. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprise a field effect diode.

9. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprises a triode.

10. The composite dipole array of claim 2, wherein:

the non-linear resonant circuits comprises a triode; and

a grid of the triode is in electrical communication with an antenna.

11. The composite dipole array of claim 2, further comprising a substrate upon which the dipoles and the non-linear resonant circuits are formed.

12. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprise:

a diode having a gap between a cathode and an anode thereof; and

a substrate upon which the diodes are formed, the substrate having a trench formed therein proximate the gap so as to mitigate perturbation of an electrical field within the gap.

13. The composite dipole array of claim 2, further comprising:

a substrate upon which the linear dipole arrays are formed; and

an insulating layer formed intermediate the linear dipole arrays and the substrate.

14. The composite dipole array of claim 2, further comprising:

a substrate upon which the linear dipole arrays are formed; and

an insulating layer formed intermediate the linear dipole arrays and the substrate, the insulating layer being formed of a plurality of dielectric layers.

15. The composite dipole array of claim 2, further comprising:

a substrate upon which the linear dipole arrays are formed; and

an insulating layer formed intermediate the linear dipole arrays and the substrate, the insulating layer being formed of a plurality of dielectric layers having thicknesses that enhances reflection at a predetermined frequency.

16. The composite dipole array of claim 2, further comprising:

a substrate upon which the linear dipole arrays are formed; and

an insulating layer formed intermediate the linear dipole arrays and the substrate, the insulating layer being formed of a plurality of dielectric layers having thicknesses that enhance transmission at a predetermined frequency.

17. The composite dipole array of claim 2, further comprising:

a substrate upon which the linear dipole arrays are formed; and

a reflector formed upon the substrate and configured so as to reflect electromagnetic radiation emitted from the composite dipole array in one direction such that it constructively interferes with electromagnetic radiation emitted from the composite dipole array in another direction.

18. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprise a diode formed of ends of the dipoles.

19. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprise a diode formed of layers of a material different from that of the dipoles proximate ends of the dipoles.

20. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprise a diode formed of layers of refractory material proximate ends of the dipoles.

21. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprise an inductor defined by a generally arc-shaped conductive path between a cathode and an anode of a diode of the non-linear resonant circuit.

22. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprise an inductor defined by two generally arc-shaped conductive paths between a cathode and an anode of a diode of the non-linear resonant circuit.

23. The composite dipole array of claim 2, wherein the non-linear resonant circuits comprise an inductor defined by two generally arc-shaped conductive paths between a cathode and an anode of a diode of the non-linear resonant circuit, at least one of the generally arc-shaped conductive paths having a capacitor formed therein

24. A method for frequency conversion, the method comprising:

directing first electromagnetic radiation of a first frequency to a composite dipole array comprising dipoles that are electrically interconnected by non-linear circuits;

directing second electromagnetic radiation of a second frequency to the composite dipole array; and

wherein the composite dipole array is resonant at a frequency approximately equal to a difference between the frequency of the first electromagnetic radiation and the second electromagnetic radiation and radiates electromagnetic radiation at a frequency approximately equal to the difference.

25. A method for forming a linear dipole array, the method comprising forming a non-linear resonant circuit intermediate adjacent dipoles.

26. The method as recited in claim 25, wherein forming a non-linear resonant circuit comprises forming a field emission device.

27. A THz electromagnetic radiation generator comprising:

a composite dipole array comprising a plurality of dipoles electrically interconnected via non-linear resonant circuits; and

two lasers configured to direct laser beams to the composite dipole array such that the laser beams cooperate with the composite dipole array to form THz electromagnetic radiation.

28. The THz electromagnetic radiation generator as recited in claim 27, wherein the lasers comprise ring type optical resonator lasers.

29. The THz electromagnetic radiation generator as recited in claim 27, wherein the lasers comprise infrared lasers.

30. The THz electromagnetic radiation generator as recited in claim 27, wherein the lasers are configured such that the laser beams are incident upon a common portion of the composite dipole array.

31. The THz electromagnetic radiation generator as recited in claim 27, wherein the lasers are configured such that the laser beams are incident upon the composite dipole array at approximately a same angle with respect to a normal to the composite dipole array.

32. The THz electromagnetic radiation generator as recited in claim 27, further comprising a transverse mode control configured to mitigate at least some transverse modes of each laser.

33. The THz electromagnetic radiation generator as recited in claim 27, further comprising a reverse mode suppressor configured to mitigate a reverse mode of each laser.

34. The THz electromagnetic radiation generator as recited in claim 27, further comprising a beam expander for expanding at least one laser beams so as to better correspond to a dimension of the composite dipole array.

35. The THz electromagnetic radiation generator as recited in claim 27, further comprising a reflector configured to reflect light from one side of the composite dipole array back toward the composite dipole array such that the reflected light constructively interferes with light from another side of the composite dipole array.

36. A THz electromagnetic radiation imaging system comprising:

a composite dipole array;

THz imaging optics configured to direct THz electromagnetic radiation to the composite dipole array;

a laser configured to direct a laser beam to the composite dipole array such that the laser beam cooperates with the THz electromagnetic radiation and the composite dipole array to form optical electromagnetic radiation.

37. The THz electromagnetic radiation imaging system as recited in claim 36, wherein the laser comprises a ring type optical resonator laser.

38. The THz electromagnetic radiation imaging system as recited in claim 36, wherein the laser comprises an infrared laser.

39. The THz electromagnetic radiation imaging system as recited in claim 36, wherein the THz imaging optics form an image upon the composite dipole array.

40. The THz electromagnetic radiation imaging system as recited in claim 36, further comprising infrared imaging optics and an imaging sensor, the infrared imaging optics being configured to form an image upon the imaging sensor using optical electromagnetic radiation from the composite dipole array.

41. The THz electromagnetic radiation imaging system as recited in claim 36, wherein laser beam cooperates with the THz electromagnetic radiation and the composite dipole array to form infrared electromagnetic radiation.

42. A method of frequency conversion, the method comprising using an interaction of electromagnetic radiation with solid-state electronics to enable frequency mixing for at least one of down conversion from optical to THz frequencies and up-conversion from THz to optical frequencies.

43. A method of frequency conversion, the method comprising using a composite dipole array to facilitate frequency mixing in the optical and THz regions.