RAPID 3D PROTOTYPING AND FABRICATING OF SLOW-WAVE STRUCTURES, INCLUDING ELECTROMAGNETIC META-MATERIAL STRUCTURES, FOR MILLIMETER-WAVELENGTH AND TERAHERTZ-FREQUENCY HIGH-POWER VACUUM ELECTRONIC DEVICES

• US 20160056005A1
• Filed: 01/23/2015
• Published: 02/25/2016
• Est. Priority Date: 08/21/2014
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Andreev, Andrey D., Moxness, J. Gregory, Peterson Lach, Maysa-Maria K.
• Granted Patent: US 10,580,611 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 2005/005 Article surface comprising protrusions
• CPC Class Codes: B22F 5/106 Tube or ring forms
• CPC Class Codes: B29L 2031/34 Electrical apparatus, e.g. sparking plugs or parts thereof
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: H01J 23/24 Slow-wave structures , e.g. delay systems
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials
• CPC Class Codes: H03F 3/58 using travelling-wave tubes
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A method for fabricating slow-wave structures, including electromagnetic meta-material structures, for high-power slow-wave vacuum electronic devices operating in millimeter-wavelength (30 GHz-300 GHz) and terahertz-frequency (300 GHz and beyond) bands of electromagnetic spectrum. The method includes: loading a digital three dimensional model of a slow-wave structure in a memory of a 3D printer, the loaded digital three dimensional model having data therein representative of the slow-wave structure to be fabricated by the 3D printer; loading metal powder material into the 3D printer; and operating the 3D printer to melt the metal powder material in accordance with the loaded three dimensional model of the slow-wave structure and then to solidify the melted layer of the metal powder material to fabricate the slow-wave structure layer by layer.

Claims

1. A method for fabrication of a slow-wave structure, comprising:

loading a digital three dimensional model of a slow-wave structure in a memory of a 3D printer, the loaded digital three dimensional model having data therein representative of the slow-wave structure to be fabricated formed by the 3D printer;

loading metal powder material into the 3D printer;

operating the 3D printer to fabricate the slow-wave structure in accordance with the loaded three dimensional model of the slow-wave structure.

2. The method recited in claim 1 wherein operating the 3D printer comprises:

depositing a layer of the metal powder material;

melting the deposited layer of the metal powder material in accordance with the loaded three dimensional model of the slow-wave structure to form a layer of melted metal; and

then solidifying the layer of melted metal to form a layer of solid metal shaped in accordance with the loaded three dimensional model of the slow-wave structure.

3. The method recited in claim 2 wherein a sequence of a plurality of the formed layers of solid metal shaped in accordance with the loaded three dimensional model of the slow-wave structure is fabricated in a stacked arrangement by the 3D printer.

4. The method recited in claim 2 wherein the slow-wave structure is dimensioned for operation in millimeter-wavelength or terahertz-frequency bands of electromagnetic spectrum.

5. The method recited in claim 2 wherein the layer of metal powder material has a thickness at least ten times less than lesser of dimensions of conductive elements of the slow-wave structure and/or distances between adjacent conductive elements of the slow-wave structure.

6. The method recited in claim 5 wherein the slow-wave structure is dimensioned for operation in millimeter-wavelength or terahertz-frequency bands of electromagnetic spectrum.

7. A slow-wave structure comprising:

a three dimensionally printed slow-wave structure dimensioned for operating in millimeter-wavelength or terahertz-frequency bands of electromagnetic spectrum.

8. A slow-wave structure, comprising:

a housing comprises a plurality of sequentially three dimensionally printed layers of solid metal shaped in accordance with a three dimensional model of the slow-wave structure.

9. The slow wave structure recited in claim 8 wherein the slow-wave structure comprises a periodic array of elements of electrically conductive material spaced one from another in both a plane and along a column disposed along a direction perpendicular to such plane.

10. The slow-wave structure recited in claim 9 wherein the elements are disposed in the plane project towards an interior region of the slow-wave structure.

11. The slow-wave structure recited in claim 10 wherein the slow-wave structure is a cylindrical structure and wherein the elements project along radial lines of the cylindrical structure.

12. The slow-wave structure recited in claim 9 wherein the elements of electrically conductive material are rod-like elements.

13. The slow-wave structure recited in claim 11 wherein the elements of electrically conductive material are rod-like elements.

14. The slow-wave structure recited in claim 9 wherein the spacing of the elements of electrically conductive material one from another is in accordance with such slow-wave structure operating in millimeter wavelength or terahertz-frequency bands of electromagnetic spectrum.

15. The slow-wave structure recited in claim 14 wherein the structure is a cylindrical structure and wherein the elements of electrically conductive material project along radial lines of the cylindrical structure.

23. The slow-wave structure recited in claim 15 wherein the width and height of elements is λ

₀/M where M is between 3.5 and 4.5 where λ

₀ is the operating wavelength of the slow wave structure.

16. A method comprising 3D printing a slow-wave structure comprising a periodic array of elements of electrically conductive material spaced one from another in both a plane and along a column disposed along a direction perpendicular to such plane.

17. The method recited in claim 16 wherein the elements of electrically conductive material are disposed in the plane project towards an interior region of the slow-wave structure.

18. The method recited in claim 17 wherein the slow-wave structure is a cylindrical structure and wherein the elements of electrically conductive material project along radial lines of the cylindrical structure.

19. The method recited in claim 16 wherein the elements of electrically conductive material are rod-like elements.

20. The method recited in claim 18 wherein the elements of electrically conductive material are rod-like elements.

21. The method recited in claim 16 wherein the spacing of the elements of electrically conductive material one from another is in accordance with such slow-wave structure operating in millimeter-wavelength or terahertz-frequency bands of electromagnetic spectrum.

22. The method recited in claim 21 wherein the slow-wave structure is a cylindrical structure and wherein the elements project along radial lines of the cylindrical structure.

24. The method recited in claim 21 wherein the thickness of the elements is λ

₀/M. where M is between 3.5 and 4.5 where λ

₀ is the operating wavelength of the slow wave structure.

25. A slow-wave structure comprising a periodic array of rows and columns of each one row of the a plurality of spaced rod-like elements disposed in a corresponding one of a spaced plurality of parallel X-Y planes, the plurality of X-Y planes being vertically stacked along a Z-axis;

distal ends of the elements being equally spaced one from another in each of the rows thereof and the X-Y planes being equally spaced one from another along a Z-axis, the Z axis being perpendicular to the X-Y planes.

26. The slow wave structure recited in claim 25 wherein the thickness of the elements is λ

₀/M where M is between 3.5 and 4.5 where λ

₀ is the operating wavelength of the slow wave structure.

27. A method comprising 3D printing a slow-wave structure comprising a periodic array of rows and columns of each one row of the a plurality of spaced rod-like elements disposed in a corresponding one of a spaced plurality of parallel X-Y planes, the plurality of X-Y planes being vertically stacked along a Z-axis;

distal ends of the elements being equally spaced one from another in each of the rows thereof and the X-Y planes being equally spaced one from another along a Z-axis, the Z axis being perpendicular to the X-Y planes.

28. The method recited in claim 27 wherein the thickness of the elements is λ

₀/M where M is between 3.5 and 4.5 where λ

₀ is the operating wavelength of the slow wave structure.

29. A method for fabricating an electromagnetic meta-material structure, comprising:

loading a digital three dimensional model of an electromagnetic meta-material structure in a memory of a 3D printer, the loaded digital three dimensional model having data therein representative of the electromagnetic meta-material structure to be formed by the 3D printer;

loading metal powder material into the 3D printer;

operating the 3D printer to fabricate the electromagnetic meta-material structure in accordance with the loaded three dimensional model of the electromagnetic meta-material structure.