Surface-mounted type antenna and communication device including the same

• US 6,501,425 B1
• Filed: 04/16/2001
• Issued: 12/31/2002
• Est. Priority Date: 09/09/1999
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Ishihara, Takashi, Tsubaki, Nobuhito, Kawahata, Kazunari, Nagumo, Shoji
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Dinh, Trinh Vo
• Application Number:
  US09/807,642
• Time in Patent Office: 624 Days
• Field of Search: H01/Q.138, 343/700.MS, 343/702, 343/895, 343/904, 343/893, 343/785, 333/202.DB, 333/204, 333/206, 333/222
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/2283 mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package
• CPC Class Codes: H01Q 1/243 with built-in antennas
• 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 1/521 reducing the coupling between adjacent antennas
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

Power non-supplied side radiation electrode 3 and power supplied side radiation electrode 4 are formed on the surface of a dielectric substrate 2 with a space therebetween. A permittivity adjusting material portion 8 is provided in the space S which is situated between the power non-supplied side radiation electrode 3 and the power supplied side radiation electrode 4, and in which a capacity occurs. The permittivity adjusting material portion 8 has a lower permittivity than that of the dielectric substrate 2, which causes the permittivity between the power non-supplied side radiation electrode 3 and the power supplied side radiation electrode 4 to be lower than that of dielectric substrate 2, and weaken the capacitive coupling between the power non-supplied side radiation electrode 3 and the power supplied side radiation electrode 4.

Claims

1. A surface-mounted type antenna comprising:

a dielectric substrate;

a first radiation electrode formed on said dielectric substrate; and

a second radiation electrode disposed on said dielectric substrate at a predetermined distance from said first radiation electrode, the first and second radiation electrodes each having respective lengths adjacent each other, further wherein;

capacitive-coupling adjusting means is provided which make the permittivity between said first radiation electrode and said second radiation electrode differ from that of said dielectric substrate, and which varies the strength of the capacitive coupling between said first radiation electrode and said second radiation electrode, said capacitive-coupling adjusting means comprising a permittivity adjusting portion which causes the capacitive coupling between the first and second radiation electrodes to vary over the adjacent lengths of the first and second radiation electrodes.

2. The surface-mounted type antenna as claimed in claim 1, wherein:

said first radiation electrode and said second radiation electrode are formed on a surface of said dielectric substrate.

3. The surface-mounted type antenna as claimed in claim 1, wherein:

said capacitive-coupling adjusting means comprises a recess or a groove formed between said first radiation electrode and said second radiation electrode, in the surface of the dielectric substrate.

4. The surface-mounted type antenna as claimed in claim 1, wherein:

the permittivity adjusting portion comprises a permittivity adjusting material portion which has a different permittivity from that of the dielectric substrate and is interposed between said first radiation electrode and said second radiation electrode.

5. The surface-mounted type antenna as claimed in claim 1, wherein:

said capacitive-coupling adjusting means comprises an area between said first radiation electrode and said second radiation electrode, said area being a hollow portion situated inside said dielectric substrate.

6. The surface-mounted type antenna as claimed in claim 1, wherein:

said first radiation electrode and said second radiation electrode are formed so that the resonance directions thereof are substantially orthogonal to each other.

7. A surface-mounted type antenna comprising:

a dielectric substrate;

a first radiation electrode formed on a surface of said dielectric substrate; and

a second radiation electrode disposed on the surface of said dielectric substrate at a predetermined distance from said first radiation electrode, wherein;

said dielectric substrate is formed by bonding a first dielectric substrate and a second dielectric substrate which has a different permittivity from that of said first dielectric substrate, a bonded portion being formed where the first and second dielectric substrates are bonded together;

said first radiation electrode is formed on said first dielectric substrate, and said second radiation electrode is formed on said second dielectric substrate; and

the bonded portion between said first dielectric substrate and said second dielectric substrate is disposed between the first radiation electrode and the second radiation electrode.

8. The surface-mounted type antenna as claimed in claim 7, wherein:

said first radiation electrode and said second radiation electrode are formed so that the resonance directions thereof are substantially orthogonal to each other.

9. A communication device comprising:

at least one of a transmitting circuit and a receiving circuit,

a surface-mounted type antenna mounted on a circuit board, the surface-mounted type antenna comprising;

a dielectric substrate;

a first radiation electrode formed on said dielectric substrate; and

a second radiation electrode disposed on said dielectric substrate at a predetermined distance from said first radiation electrode, the first and second radiation electrodes each having respective lengths adjacent each other, further wherein;

capacitive-coupling adjusting means is provided which make the permittivity between said first radiation electrode and said second radiation electrode differ from that of said dielectric substrate, and which varies the strength of the capacitive coupling between said first radiation electrode and said second radiation electrode, said capacitive-coupling adjusting means comprising a permittivity adjusting portion which causes the capacitive coupling between the first and second radiation electrodes to vary over the adjacent lengths of the first and second radiation electrodes.

10. The communication device as claimed in claim 9, wherein:

said first radiation electrode and said second radiation electrode are formed on a surface of said dielectric substrate.

11. The communication device as claimed in claim 9, wherein:

said capacitive-coupling adjusting means comprises a recess or a groove formed between said first radiation electrode and said second radiation electrode, in the surface of the dielectric substrate.

12. The communication device as claimed in claim 9, wherein:

the permittivity adjusting portion comprises a permittivity adjusting material portion which has a different permittivity from that of the dielectric substrate and is interposed between said first radiation electrode and said second radiation electrode.

13. The communication device as claimed in claim 9, wherein:

said capacitive-coupling adjusting means comprises an area between said first radiation electrode and said second radiation electrode, said area being a hollow portion situated inside said dielectric substrate.

14. The communication device as claimed in claim 9, wherein:

said first radiation electrode and said second radiation electrode are formed so that the resonance directions thereof are substantially orthogonal to each other.

15. A communication device comprising:

at least one of a transmitter circuit and a receiving circuit;

a surface-mounted type antenna mounted on a circuit board, the surface-mounted type antenna comprising;

a dielectric substrate;

a first radiation electrode formed on a surface of said dielectric substrate; and

a second radiation electrode disposed on the surface of said dielectric substrate at a predetermined distance from said first radiation electrode, wherein;

said dielectric substrate is formed by bonding a first dielectric substrate and a second dielectric substrate which has a different permittivity from that of said first dielectric substrate, a bonded portion being formed where the first and second dielectric substrates are bonded together;

said first radiation electrode is formed on said first dielectric substrate, and said second radiation electrode is formed on said second dielectric substrate; and

the bonded portion between said first dielectric substrate and said second dielectric substrate is disposed between the first radiation electrode and the second radiation electrode.

16. The communication device as claimed in claim 15, wherein:

said first radiation electrode and said second radiation electrode are formed so that the resonance directions thereof are substantially orthogonal to each other.

17. A surface-mounted type antenna comprising:

a dielectric substrate;

a first radiation electrode formed on said dielectric substrate; and

a second radiation electrode disposed on said dielectric substrate at a predetermined distance from said first radiation electrode, the first and second radiation electrodes each having respective lengths adjacent each other, further wherein;

a capacitive-coupling adjusting portion is provided which make the permittivity between said first radiation electrode and said second radiation electrode differ from that of said dielectric substrate, and which varies the strength of the capacitive coupling between said first radiation electrode and said second radiation electrode, said capacitive-coupling adjusting portion comprising a permittivity adjusting portion which causes the capacitive coupling between the first and second radiation electrodes to vary over the adjacent lengths of the first and second radiation electrodes.

18. The surface-mounted type antenna as claimed in claim 17, wherein the width of said capacitive coupling adjusting portion varies over the lengths of the first and second radiation electrodes.