Phase shift of signal reflections of surface traveling waves

Patent metadata

Field	Value
Publication number	US-10116023-B2
Application number	US-201615332455-A
Country	US
Kind code	B2
Filing date	Oct 24, 2016
Priority date	Oct 24, 2016
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

An apparatus is provided for causing a phase-shift in reflected signals that are a reflection of surface-traveling wave signals of a select signal frequency. The apparatus comprises a conductive strip having a plurality of slots therein alternatingly arranged orthogonal to each other, each slot having an effective length that is a fraction between 9/16 and ⅞ of the wavelength associated with the select signal frequency, and a plurality of conductive enclosures respectively disposed under each of the plurality of slots. Each of the conductive enclosure have a width and length sufficient to enclose a respective corresponding slot, and a depth that is a fraction of between ⅛ and ⅜ of the wavelength associated with the select signal frequency when transmitted in the dielectric material. The plurality of slots and plurality of conductive enclosures cause a phase-shift in the range of 150 to 210 degrees in reflected signals that are a reflection of surface-traveling wave signals at the select signal frequency which impinge the apparatus.

First claim

What is claimed is:

1. An apparatus configured to cause a phase-shift in reflected signals that are a reflection of surface-traveling wave signals of a select signal frequency, comprising:
a conductive strip, having a plurality of slots therein alternatingly arranged orthogonal to each other, each slot having a length that is a fraction of between 9/16 and ⅞ of a wavelength λ 0 associated with the select signal frequency;
a plurality of conductive enclosures respectively disposed under each of the plurality of slots, each conductive enclosure having a width and length sufficient to enclose a respective corresponding slot, wherein each of the conductive enclosures have a dielectric material therein and have a depth that is a fraction of between ⅛ and ⅜ of a wavelength λ d associated with the select signal frequency when transmitted in the dielectric material;
wherein the plurality of slots and plurality of conductive enclosures cause a phase-shift in the range of 150 to 210 degrees in the reflected signals that are a reflection of the surface-traveling wave signals at the select signal frequency which impinge the apparatus.

2. The apparatus of claim 1 , wherein each of the slots have the length that is about ¾ of the wavelength λ 0 associated with the select signal frequency.

3. The apparatus of claim 1 , wherein the plurality of slots are spaced apart in a manner such that a distance between center points of adjacent slots are between 0.7 and 1.0 of the wavelength λ 0 associated with the select signal frequency.

4. The apparatus of claim 3 , wherein each of the plurality of conductive enclosures define a shielded enclosure forming a reflecting interior with the depth that is between ⅛ and ⅜ of the wavelength λ d associated with the select signal frequency when transmitted in the dielectric material, which establishes an anti-resonant cavity that causes the phase-shift in the range of 150 to 210 degrees in reflected signals that are reflected from surface-traveling wave signals at the select signal frequency.

5. The apparatus of claim 3 , wherein the depth of each of the conductive enclosures is about ¼ of the wavelength λ d associated with the select signal frequency when transmitted in the dielectric material.

6. The apparatus of claim 5 , wherein the dielectric material has a relative permeability that is effective to establish an impedance discontinuity at each slot's inlet that is sufficient to cause the phase-shift in the range of 150 to 210 degrees in reflected signals that are the reflection of surface-traveling wave signals at the select signal frequency.

7. The apparatus of claim 5 , wherein the dielectric material has a relative permeability that is between 1 and 10.

8. The apparatus of claim 7 , wherein the dielectric material has a relative permittivity between 1 and 20.

9. The apparatus of claim 8 , further comprising a surface structure of a vehicle on which the apparatus is disposed, where the apparatus is disposed on the surface proximate to a surface irregularity on the surface.

10. The apparatus of claim 9 , wherein the phase-shifted reflected signals that are reflections of surface-traveling wave signals at the select signal frequency cause a signal-cancelling effect, relative to reflections of surface-traveling wave signals at the select signal frequency that are reflected by the surface irregularity, such that the apparatus effectively filters reflected signals of surface-traveling wave signals at the select signal frequency.

11. The apparatus of claim 5 , wherein the plurality of conductive enclosures include the dielectric material with a relative permeability between 1.0 and 3.0, and have the depth of about ¼ of the effective wavelength λ d associated with the select signal frequency when transmitted in the dielectric material, whereby the apparatus has a minimal profile height of between 1.5 centimeters and 2.0 centimeters as a result of the shorter effective wavelength λ d of the select signal when transmitted in the dielectric material.

12. A method for producing an apparatus for causing a phase-shift in reflected signals that are a reflection of surface-traveling wave signals of a select signal frequency, comprising the steps of:
forming a plurality of slots in a conductive strip, alternatingly arranged orthogonal to each other, each slot having a length that is a fraction of between 9/16 and ⅞ of a wavelength λ 0 associated with the select signal frequency;
affixing a plurality of conductive enclosures to the conductive strip, with each of the conductive enclosures respectively disposed under each of the plurality of slots and having a width and length sufficient to enclose a corresponding respective slot, each of the conductive enclosures including a dielectric material therein and having a depth that is a fraction of between ⅛ and ⅜ of a wavelength λ d associated with the select signal frequency when transmitted in the dielectric material;
whereby the plurality of slots and plurality of conductive enclosures cause a phase-shift in the range of 150 to 210 degrees in the reflected signals that are a reflection of the surface-traveling wave signals at the select signal frequency which impinge the apparatus.

13. The method of claim 12 , wherein forming the plurality of slots comprises forming slots having a length that is about ¾ of the wavelength λ 0 associated with the select signal frequency.

14. The method of claim 13 , wherein forming the plurality of slots comprises forming the plurality of slots to be spaced apart in a manner such that a distance between center points of adjacent slots are between 0.7 and 1.0 of the wavelength Δ 0 associated with the select signal frequency.

15. The method of claim 14 , wherein the step of affixing the plurality of conductive enclosures comprises affixing conductive enclosures having the depth of about ¼ of the effective wavelength λ d associated with the select signal frequency when transmitted through the dielectric material in the conductive enclosures.

16. The method of claim 15 , further comprising the step of including the dielectric material with a relative permeability of between 1 and 10 within each of the conductive enclosures, in an amount that is effective to define a shielded enclosure generally establishing an anti-resonant cavity, such that the conductive enclosures cause the phase-shift in the range of 150 to 210 degrees in the reflected signals that are reflected from surface-traveling wave signals at the select signal frequency.

17. The method of claim 16 , wherein the step of including the dielectric material comprises including a low-loss dielectric material having a relative permeability between 1 and 1.5 and a relative permittivity between 1 and 4.6, whereby the apparatus has a minimal profile height of between 1.5 centimeters and 2.0 centimeters as a result of the shorter effective wavelength λ d associated with the select signal frequency when transmitted through the dielectric material.

18. The method of claim 16 , wherein the step of including the dielectric material comprises including one of an epoxy and a fiberglass material.

19. The method of claim 16 , further comprising the step of installing the apparatus onto a vehicle proximate to a surface irregularity on the vehicle.

20. The method of claim 16 , further comprising the step of installing the apparatus onto a vehicle proximate to a surface irregularity on the vehicle, such that the phase-shifted reflected signals that are reflected from surface-traveling wave signal

Assignees

• Boeing Co

Inventors

• Gilchrist Garrett L
• Burns Richard W
• Hurst Michael P

Classifications

• H01Q13/18

  the slot being backed by, or formed in boundary wall of, a resonant cavity (longitudinally slotted cylinder H01Q13/12 ){; Open cavity antennas} · CPC title

• H01Q1/52

  Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure (absorbing means H01Q17/00) · CPC title

• H01Q15/006 Primary

  Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces · CPC title

• H01Q13/28

  comprising elements constituting electric discontinuities and spaced in direction of wave propagation, e.g. dielectric elements or conductive elements forming artificial dielectric · CPC title

• H01Q3/32

  by mechanical means · CPC title