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 10,580,611 B2
• Filed: 01/23/2015
• Issued: 03/03/2020
• 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.
• Primary Examiner(s): Luk, Vanessa T.
• Application Number:
  US14/603,987
• Publication Number:
  US 20160056005A1
• Time in Patent Office: 1,866 Days
• Field of Search: 315 35, 315 393, 315 36, 315 4, 315 5, 315 511, 315 512, 315 513, 315 514, 315 515, 315 516, 315 517, 315 518, 315 519, 315 521, 315 522, 315 523, 315 524, 315 525, 315 526, 315 527, 315 528, 315 529, 315 531, 315 532, 315 533, 315 534, 315 535, 315 536, 315 537, 315 538, 315 539, 315 541, 315 542, 315 543, 315 544, 315 545, 315 546, 315 547, 315 548, 315 549, 315 551, 315 552, 315 553, 315 554, 315 7, 333138-164
• 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, comprising:

3D printing a slow-wave structure, the slow wave structure comprising;

a unitary structure comprising;

an outer wall extending longitudinally along a z-axis, the z-axis being perpendicular to an x-y plane, the outer wall enclosing a central region; and

a plurality of sections, the sections being angularly spaced one from another around the central region, each one of the sections comprising;

a periodic array of elements of electrically conductive material projecting radially inwardly from the outer wall in the x-y plane and terminating in the central region, the elements in each one of the sections being angularly spaced one from another in both the x-y plane and along columns disposed along parallel to the z-axis;

wherein each one of the sections comprises;

a plurality of rows of the elements, the elements in each one of the rows being angularly spaced one from another, and a plurality of columns of the elements, the elements in each one of the columns being angularly spaced one from another; and

wherein the angularly spacing between the sections is greater than the angularly spacing between the elements in each one of the columns and each one of the rows.

2. A method comprising:

3D printing a slow-wave structure, the slow-wave structure comprising;

a unitary structure comprising;

an outer wall extending longitudinally along a z-axis, the z-axis being perpendicular to an x-y plane, the outer wall enclosing a central region; and

a plurality of sections, the sections being angularly spaced one from another around the central region, each one of the sections comprising;

a periodic array of rows and columns of angularly spaced rod-like elements disposed in a corresponding one of a angularly 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 angularly spaced one from another in each of the rows thereof and the X-Y planes being equally angularly spaced one from another along a Z-axis, the Z axis being perpendicular to the X-Y planes, the rod-like elements projecting radially inwardly from the outer wall and terminating in the central region;

wherein each one of the sections comprises;

a plurality of rows of the rod-like elements, the rod-like elements in each one of the rows being angularly spaced one from another; and

a plurality of columns of the rod-like elements, the rod-like elements in each one of the columns being angularly spaced one from another; and

wherein the spacing between the sections is greater than the spacing between the rod-like elements in each one of the columns and each one of the rows.

3. 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;

wherein the elements of electrically conductive material are disposed in the plane project towards an interior region of the slow-wave structure;

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 and comprising a periodic array of rows and columns of each one row of 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, 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, and wherein the slow-wave structure operates at frequencies corresponding to millimeter-wavelength and terahertz-frequency bands of the electromagnetic spectrum.