Composite dielectric molded product and lens antenna using the same

• US 6,489,928 B2
• Filed: 10/17/2001
• Issued: 12/03/2002
• Est. Priority Date: 10/18/2000
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Sakurada, Kiyoyasu
• Primary Examiner(s): PHAN, THO GIA
• Application Number:
  US09/978,745
• Publication Number:
  US 20020067317A1
• Time in Patent Office: 412 Days
• Field of Search: H01/Q 1.906, 343/753, 343/909, 343/911.R, 343/910, 343/911.L, 752/30, 428/209, 428/325, 428/548, 419/10, 419/29
• US Class Current: 343/753
• CPC Class Codes: H01B 3/12 ceramics
• CPC Class Codes: H01B 3/30 plastics; resins; waxes
• CPC Class Codes: H01Q 15/08 formed of solid dielectric material
• CPC Class Codes: H01Q 15/10 comprising three-dimensional array of impedance discontinuities, e.g. holes in conductive surfaces or conductive discs forming artificial dielectric
• CPC Class Codes: H01Q 19/08 for modifying the radiation pattern of a radiating horn in which it is located corrugated horns H01Q13/0208; producing a circular polarisation H01Q13/0241
• CPC Class Codes: Y10T 428/24917 including metal layer

Abstract

Provided is a composite dielectric molded product exhibiting excellent properties such as the antenna gain and side lobe, etc. when used for a lens antenna, and exhibiting less variation of properties in one individual product and between individual products. The composite dielectric molded product is formed by molding a composite dielectric material containing a dielectric inorganic filler and an organic polymer material so that the dielectric constant anisotropy is in the range of about 1.00 to 1.05.

Claims

1. A composite dielectric molded product comprising a composite dielectric material containing a dielectric inorganic filler and an organic polymer material;

wherein the dielectric constant anisotropy, which is the ratio (A/B) of dielectric constant A in a direction in which the dielectric constant is maximum to dielectric constant B in a direction in which the dielectric constant is minimum, is in the about 1.00 to 1.05.

2. A composite dielectric molded product according to claim 1, wherein the dielectric inorganic filler is about 1-55 vol % of the composite dielectric material.

3. A composite dielectric molded product according to claim 2, wherein the dielectric inorganic filler is about 10-55 vol % of the composite dielectric material.

4. A composite dielectric molded product according to claim 2, wherein the composite dielectric material has a melt viscosity of about 170 Pa·

s or more at a shear rate of 1000 S<sup>−

1</sup>.

5. A composite dielectric molded product according to claim 1, wherein the composite dielectric material has a melt viscosity of about 170 Pa·

s or more at a shear rate of 1000 S<sup>−

1</sup>.

6. A composite dielectric molded product according to claim 1, wherein the organic polymer material comprises a thermoplastic resin.

7. A composite dielectric molded product according to claim 1, wherein the organic polymer material comprises a thermoplastic resin containing a resin filler.

8. A composite dielectric molded product according to claim 7, wherein the resin filler is about 1-45 vol % of the organic polymer material.

9. A composite dielectric molded product according to claim 1, wherein the dielectric inorganic filler is at least one member selected from the group consisting of oxides, carbonates, phosphates and silicates of IIa, IVa, IIIb or IVb group elements, and compound oxides containing IIa, IVa, IIIb or IVb group elements.

10. A composite dielectric molded product according to claim 1, wherein the dielectric inorganic filler is about 1-55 vol % of the composite dielectric material, and the composite dielectric material has a melt viscosity of about 170 Pa·

s or more at a shear rate of 1000 S<sup>−

1</sup>.

11. A composite dielectric molded product according to claim 10, wherein the dielectric inorganic filler is about 10-55 vol % of the composite dielectric material, the organic polymer material comprises a thermoplastic resin and wherein the composite dielectric material has a melt viscosity of about 200 to 8000 Pa·

s at a shear rate of 1000 S<sup>−

1</sup>.

12. A lens antenna comprising at least a lens unit having a convex outgoing plane, and a primary transmitter behind the lens unit;

wherein the lens unit comprises a composite dielectric molded product according to claim 11.

13. A lens antenna according to claim 12, wherein the lens unit comprises a lens body having a surface and a matching layer on the surface of the lens body, for matching the lens body with the air.

14. A lens antenna according to claim 13, wherein the matching layer has a relative dielectric constant which is approximately the same as the square root of the relative dielectric constant of the lens body.

15. A lens antenna comprising at least a lens unit having a convex outgoing plane, and a primary transmitter behind the lens unit;

wherein the lens unit comprises a composite dielectric molded product according to claim 5.

16. A lens antenna according to claim 15, wherein the lens unit comprises a lens body having a surface and a matching layer on the surface of the lens body, for matching the lens body with the air.

17. A lens antenna according to claim 16, wherein the matching layer has a relative dielectric constant which is approximately the same as the square root of the relative dielectric constant of the lens body.

18. A lens antenna comprising at least a lens unit having a convex outgoing plane, and a primary transmitter behind the lens unit;

wherein the lens unit comprises a composite dielectric molded product according to claim 1.

19. A lens antenna according to claim 18, wherein the lens unit comprises a lens body having a surface and a matching layer on the surface of the lens body, for matching the lens body with the air.

20. A lens antenna according to claim 19, wherein the matching layer has a relative dielectric constant which is approximately the same as the square root of the relative dielectric constant of the lens body.