High-frequency signal transmission line and electronic device

• US 9,401,531 B2
• Filed: 02/27/2014
• Issued: 07/26/2016
• Est. Priority Date: 02/03/2012
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Iida, Kanto, Tago, Shigeru
• Primary Examiner(s): Jones, Stephen E
• Application Number:
  US14/191,595
• Publication Number:
  US 20140176254A1
• Time in Patent Office: 880 Days
• Field of Search: 333/238, 333/246, 333/33, 333/34
• US Class Current: 1/1
• CPC Class Codes: H01P 3/08 Microstrips; Strip lines
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H05K 1/0225 Single or multiple openings in a shielding, ground or power plane H05K1/0227 takes precedence
• CPC Class Codes: H05K 1/0253 Impedance adaptations of transmission lines by special lay-out of power planes, e.g. providing openings H05K1/0251 takes precedence
• CPC Class Codes: H05K 2201/09327 Special sequence of power, ground and signal layers in multilayer PCB
• CPC Class Codes: H05K 2201/09618 Via fence, i.e. one-dimensional array of vias
• CPC Class Codes: H05K 2201/09672 Superposed layout, i.e. in different planes
• CPC Class Codes: H05K 2201/09727 Varying width along a single conductor; Conductors or pads having different widths

Abstract

A high-frequency signal transmission line includes a dielectric body including a plurality of dielectric sheets. A signal line is provided in the dielectric body. A connector is mounted on a first main surface of the dielectric body and electrically connected to the signal line. A ground conductor is provided on a second main surface side of the dielectric body, compared with the signal line, and faces the signal line across the dielectric sheet. In the ground conductor, conductor-missing portions are provided in which no conductors are provided in at least portions of regions overlapping with the signal line in planar in connection portions. Adjustment conductors are provided in the second main surface of the dielectric body, and overlap with at least portions of the conductor-missing portions in the planar view.

Claims

1. A high-frequency signal transmission line comprising:

a body including a plurality of insulator layers laminated on each other;

a linear signal line provided in or on the body;

a first ground conductor facing the signal line across at least one of the plurality of insulator layers; and

an adjustment conductor;

wherein

the body includes a connection portion in which the signal line and an external circuit are electrically connected in a first main surface of the body, and a line portion in which the signal line is provided, the line portion extending from the connection portion;

in the first ground conductor, a conductor-missing portion is provided in at least a portion of a region overlapping with the signal line, in a planar view from a lamination direction in the connection portion; and

the adjustment conductor is provided in a second main surface of the body, and overlaps with at least a portion of the conductor-missing portion in the planar view from the lamination direction; and

the adjustment conductor is not provided in the line portion.

2. The high-frequency signal transmission line according to claim 1, wherein a portion of the adjustment conductor overlaps with the signal line in the planar view of the body from the lamination direction.

3. The high-frequency signal transmission line according to claim 1, wherein the adjustment conductor includes an insulating substrate in which a metal plate or a conductor layer is provided.

4. The high-frequency signal transmission line according to claim 1, wherein the adjustment conductor is fixed to the body via an adhesive or a resist material.

5. The high-frequency signal transmission line according to claim 1, wherein the adjustment conductor is not electrically connected to the signal line or the first ground conductor.

6. The high-frequency signal transmission line according to claim 1, wherein the first ground conductor is provided on the first main surface side of the body, compared with the signal line.

7. The high-frequency signal transmission line according to claim 1, further comprising:

an external electrode provided on the first main surface of the connection portion of the body and electrically connected to the signal line;

wherein

the signal line is electrically connected to the external circuit through the external electrode.

8. The high-frequency signal transmission line according to claim 1, wherein capacitance is generated between the adjustment conductor and the signal line and capacitance is generated between the adjustment conductor and the first ground conductor.

9. The high-frequency signal transmission line according to claim 1, further comprising:

a second ground conductor provided on the first main surface side of the body, compared with the signal line, and facing the signal line across at least one of the plurality of insulator layers;

wherein

the first ground conductor is provided on the second main surface side of the body, compared with the signal line; and

a plurality of openings are provided in at least one of the first ground conductor and the second ground conductor, the plurality of openings being arranged along the signal line in the planar view from the lamination direction.

10. The high-frequency signal transmission line according to claim 9, wherein

a characteristic impedance of the signal line in a first region overlapping with the openings is higher than a characteristic impedance of the signal line in a second region not overlapping with the openings;

and

the characteristic impedance of the signal line in the first region and the characteristic impedance of the signal line in the second region are set so that a characteristic impedance of an entirety of the signal line is a predetermined characteristic impedance.

11. The high-frequency signal transmission line according to claim 1, further comprising:

a connector is mounted on the first main surface of the connection portion of the body, and is electrically connected to the signal line;

wherein

the signal line is electrically connected to the external circuit through the connector.

12. The high-frequency signal transmission line according to claim 11, wherein the adjustment conductor is configured such that a characteristic impedance of the connector has a predetermined characteristic impedance.

13. An electronic device comprising:

a high-frequency signal transmission line; and

a housing containing the high-frequency signal transmission line;

wherein

the high-frequency signal transmission line includes;

a body including a plurality of insulator layers laminated on each other;

a linear signal line provided in or on the body;

a first ground conductor facing the signal line across at least one of the plurality of insulator layers; and

an adjustment conductor;

wherein

the body includes a connection portion in which the signal line and an external circuit are electrically connected in a first main surface of the body, and a line portion in which the signal line is provided, the line portion extending from the connection portion;

in the first ground conductor, a conductor-missing portion is provided in at least a portion of a region overlapping with the signal line, in a planar view from a lamination direction in the connection portion; and

the adjustment conductor is provided in a second main surface of the body, and overlaps with at least a portion of the conductor-missing portion in the planar view from the lamination direction; and

the adjustment conductor is not provided in the line portion.

14. The electronic device according to claim 13, wherein a portion of the adjustment conductor overlaps with the signal line in the planar view of the body from the lamination direction.

15. The electronic device according to claim 13, wherein the adjustment conductor includes an insulating substrate in which a metal plate or a conductor layer is provided.

16. The electronic device according to claim 13, wherein the adjustment conductor is fixed to the body via an adhesive or a resist material.

17. The electronic device according to claim 13, wherein the adjustment conductor is not electrically connected to the signal line or the first ground conductor.

18. The electronic device according to claim 13, wherein the first ground conductor is provided on the first main surface side of the body, compared with the signal line.

19. The electronic device according to claim 13, further comprising:

a second ground conductor provided on the first main surface side of the body, compared with the signal line, and facing the signal line across at least one of the plurality of insulator layers;

wherein

the first ground conductor is provided on the second main surface side of the body, compared with the signal line; and

a plurality of openings are provided in at least one of the first ground conductor and the second ground conductor, the plurality of openings being arranged along the signal line in the planar view from the lamination direction.

20. The electronic device according to claim 19, wherein

a characteristic impedance of the signal line in a first region overlapping with the openings is higher than a characteristic impedance of the signal line in a second region not overlapping with the openings;

and

the characteristic impedance of the signal line in the first region and the characteristic impedance of the signal line in the second region are set so that a characteristic impedance of an entirety of the signal line is a predetermined characteristic impedance.