Antenna for portable terminal and portable terminal using same

• US 20060119518A1
• Filed: 02/17/2004
• Published: 06/08/2006
• Est. Priority Date: 02/18/2003
• Status: Active Grant

• Current Assignee: Tadahiro Ohmi
• Original Assignee: Tadahiro Ohmi
• Inventors: Ohmi, Tadahiro, Morimoto, Akihiro, Nakamura, Fumiaki
• Granted Patent: US 7,995,001 B2
• Time in Patent Office: Days
• US Class Current: 343/700.MS
• CPC Class Codes: H01Q 9/0485 Dielectric resonator antennas

Abstract

A dielectric resonator antenna which emits an electric wave by having a dielectric body resonate is disclosed. A magnetic material is contained in the electric body, thereby increasing the relative permeability to more than 1 and lowering the relative permittivity. Consequently, the Q-value of the resonance can be lowered while maintaining the rate of wavelength shortening. With this technique, a broadband dielectric resonator antenna can be realized.

Claims

1. A dielectric resonator antenna comprising a dielectric made of an insulator material and an electrode provided outside or inside said dielectric, said dielectric resonator antenna being adapted to emit a radio wave to the exterior by resonating a signal supplied into said dielectric from said electrode, said dielectric having a relative permeability (μ

ra) of μ

ra>

1.

2. The dielectric resonator antenna according to claim 1, wherein said dielectric is mounted on a conductive plate, provided as a reflecting plate, directly or via an insulator having a relative permittivity ε

rd>

1.

3. The dielectric resonator antenna according to claim 2, wherein, given that a relative permeability is ε

rr and a relative permittivity is ε

rr, a magneto-dielectric layer having a relationship of ε

rr≧

ε

rr is provided on a surface, opposite to a dielectric mounting surface, of said reflecting plate.

4. The dielectric resonator antenna according to claim 1, wherein said dielectric contains a magnetic material and a dielectric material.

6. The dielectric resonator antenna according to claim 4, wherein a wavelength shortening coefficient is 200 or less.

7. The dielectric resonator antenna according to claim 4, wherein a wavelength shortening coefficient is 100 or less.

8. The dielectric resonator antenna according to claim 4, wherein a wavelength shortening coefficient is 50 to 3.

9. The dielectric resonator antenna according to claim 4, wherein said magnetic material contains at least one of a simple substance of cobalt, manganese, or iron, and an alloy and a compound magnetic material each containing at least one of cobalt, manganese, and iron.

10. The dielectric resonator antenna according to claim 4, wherein said dielectric material contains one or both of a resin material containing at least one of liquid crystal resin, epoxy resin, olefin-based resin, fluororesin, BT (bismaleimide triazine) resin, and polyimide resin and an inorganic dielectric material containing at least one of silica (SiO₂, SiO), silicon nitride (SiN, Si₃N₄), zirconia (ZrO, ZrO₂), hafnia (HfO, HfO₂), titania (TiO, TiO₂), aluminum nitride (AlN), SrBi₂Ta₂O₉, SrBi₂(Ta_1-x,Nb_x)₂O₉, Sr₂(Ta_1-x,Nb_x)₂O₇, BST (barium strontium titanate), PZT (lead zirconate titanate), alumina (Al₂O₃), BiTiO₃, SrTiO₃, PbZrO₃, PbTiO₃, and CaTiO₃.

11. The dielectric resonator antenna according to claim 10, wherein fine powder of said magnetic material is dispersed into said resin material.

12. The dielectric resonator antenna according to claim 11, wherein said inorganic dielectric material is further dispersed into said resin material.

13. The portable terminal including the dielectric resonator antenna according to claim 1.

14. The portable terminal including a plurality of dielectric resonator antennas each according to claim 1 and being capable of adjusting a radio wave radiation direction.

5. A dielectric resonator antenna comprising a resonator formed by the use of a dielectric having a relative permittivity and a relative permeability that realize frequency vs. antenna input impedance characteristics so as to partly share half frequencies of resonance peaks of a first mode on a low frequency side and a second mode on a high frequency side.

15. A method of manufacturing a dielectric resonator antenna that emits a radio wave by radiating a radio wave to a resonator formed by a dielectric and resonating said radiated radio wave in said dielectric, said method comprising:

adjusting a relative permittivity on condition that a relative permeability exceeds 1, to thereby obtain a magneto-dielectric material that can achieve a predetermined wavelength shortening coefficient; and

forming said dielectric by the use of said magneto-dielectric material.

16. The method according to claim 15, wherein said magneto-dielectric material is produced by mixing together a magnetic material and a dielectric material.

17. The method according to claim 16, wherein said magnetic material contains at least one of a simple substance of cobalt, manganese, or iron, and an alloy and a compound magnetic material each containing at least one of cobalt, manganese, and iron.

18. The method according to claim 16, wherein said dielectric material contains one or both of a resin material containing at least one of liquid crystal resin, epoxy resin, olefin-based resin, fluororesin, BT (bismaleimide triazine) resin, and polyimide resin and an inorganic dielectric material containing at least one of silica (SiO₂, SiO), silicon nitride (SiN, Si₃N₄), zirconia (ZrO, ZrO₂), hafnia (HfO, HfO₂), titania (TiO, TiO₂), aluminum nitride (AlN), SrBi₂Ta₂O₉, SrBi₂(Ta_1-x,Nb_x)₂O₉, Sr₂(Ta_1-x,Nb_x)₂O₇, BST (barium strontium titanate), PZT (lead zirconate titanate), alumina (Al₂O₃), BiTiO₃, SrTiO₃, PbZrO₃, PbTiO₃, and CaTiO₃.

19. The method according to claim 18, further comprising dispersing fine powder of said magnetic material into said resin material.

20. The method according to claim 19, further comprising dispersing said inorganic dielectric material into said resin material.