Dielectric substrate with selectively controlled effective permittivity and loss tangent

• US 6,992,636 B2
• Filed: 04/29/2005
• Issued: 01/31/2006
• Est. Priority Date: 06/19/2003
• Status: Expired due to Fees

• Current Assignee: North South Holdings Incorporated (Spherix Incorporated)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Tebbe, Dennis, Smyth, Thomas, Chappell, William Johnson
• Primary Examiner(s): Dinh, Trinh Vo
• Application Number:
  US11/118,445
• Publication Number:
  US 20050200532A1
• Time in Patent Office: 277 Days
• Field of Search: 343/700.MS, 343/756, 343/909, 333/128, 333/204, 333/108, 156/89.11, 156/89.12, 156/89.1
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 15/006 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 Class Codes: H05K 1/024 Dielectric details, e.g. changing the dielectric material around a transmission line
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2203/063 of preperforated insulating layer
• CPC Class Codes: H05K 3/4611 by laminating two or more circuit boards H05K3/4652 takes precedence
• CPC Class Codes: H05K 3/4629 laminating inorganic sheets comprising printed circuits, e.g. green ceramic sheets
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

A substrate (300) for an RF device includes a plurality of layers (102) of dielectric material cofired in a stack. The plurality of layers (102) is formed from a material having a permittivity. Selected ones of the layers (102) have a pattern of perforations (106) formed in at least one perforated area (104). The perforated areas (104) are generally aligned with one another in the stack to lower one or more of an effective value of a permittivity and a loss tangent in a least one spatially defined region (504) of the substrate (300).

Claims

1. A substrate for an RF device, comprising:

a plurality of layers of dielectric material cofired in a stack, each of said plurality of layers formed from a material having a permittivity and having a pattern of perforations formed in at least one perforated area; and

said perforated areas of each respective one of said plurality of layers at least partially aligned with one another in said stack to lower at least one of an effective value of a permittivity and a loss tangent in at least one spatially defined region of said substrate, wherein said effective permittivity varies in a predetermined manner across a surface of said substrate defined by said spatially defined region in accordance with a variation of said pattern of said perforations.

2. The substrate according to claim 1 wherein said plurality of layers are comprised of a ceramic tape.

3. The substrate according to claim 1 wherein said plurality of layers are comprised of a low temperature type cofired ceramic tape.

4. The substrate according to claim 1 wherein said perforations of each said perforated area are aligned with one another.

5. The substrate according to claim 1 wherein said pattern of perforations is excluded from at least one outermost layer of said substrate.

7. The substrate according to claim 1 wherein said pattern of perforations is varied among said plurality of layers.

8. The substrate according to claim 1 wherein said pattern of perforations is offset from layer to layer.

9. The substrate according to claim 1 wherein said pattern of perforations is formed in a plurality of said perforated areas of each said layer to produce a plurality of said spatially defined regions, each having at least one of an effective value of permittivity and a loss tangent lower than a permittivity and loss tangent for said dielectric material.

10. The substrate according to claim 9 wherein said pattern of perforations in said plurality of perforated areas produces different values for at least one of said effective permittivity and said loss tangent in at least a first one of said spatially defined regions as compared to at least a second one of said spatially defined regions.

6. A substrate for an RF device, comprising:

a plurality of layers of dielectric material cofired in a stack, each of said plurality of layers formed from a material having a permittivity and having a pattern of perforations formed in at least one perforated area; and

said perforated areas of each respective one of said plurality of layers at least partially aligned with one another in said stack to lower at least one of an effective value of a permittivity and a loss tangent in at least one spatially defined region of said substrate, wherein said pattern of perforations for each of said plurality of layers is arranged so that said effective value of permittivity is substantially the same at each measurable point of said spatially defined region of said substrate.

11. A substrate for an RF device, comprising:

a plurality of layers of dielectric material cofired in a stack, each of said plurality of layers formed from a material having a permittivity and having a pattern of perforations formed in at least one perforated area; and

said perforated areas of each respective one of said plurality of layers at least partially aligned with one another in said stack to lower at least one of an effective value of a permittivity and a loss tangent in at least one spatially defined region of said substrate, wherein said pattern of perforations in each of said layers causes said effective permittivity to selectively vary in a predetermined manner across a surface of said substrate defined by said spatially defined region.