Wireless IC device

• US 8,944,335 B2
• Filed: 01/10/2013
• Issued: 02/03/2015
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Dokai, Yuya, Ozawa, Masahiro
• Primary Examiner(s): Lee, Michael G
• Assistant Examiner(s): TARDIF, DAVID P
• Application Number:
  US13/738,143
• Publication Number:
  US 20130140369A1
• Time in Patent Office: 754 Days
• Field of Search: 235/492
• US Class Current: 235/492
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: H01L 2223/6677 for antenna, e.g. antenna included within housing of semiconductor device
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/19105 in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• 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 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H05K 1/182 associated with components mounted in the printed circuit board, e.g. insert mounted components [IMC]

Abstract

A wireless IC device that improves radiation gain without increasing substrate size and easily adjusts impedance, includes a multilayer substrate including laminated base layers. On a side of an upper or first main surface of the multilayer substrate, a wireless IC element is arranged to process a high-frequency signal. On a side of a lower or second main surface of the multilayer substrate, a first radiator is provided and is coupled to the wireless IC element via a feeding circuit including first interlayer conductors. On the side of the first main surface, a second radiator is provided and is coupled to the first radiator via second interlayer conductors.

Claims

1. A wireless IC device comprising:

a substrate including a first main surface and a second main surface facing the first main surface;

a wireless IC element provided on a side of the first main surface and arranged to process a high-frequency signal;

a first radiator including first and second ends, provided on a side of the second main surface, and coupled to the wireless IC element via a feeding circuit including a first interlayer conductor; and

a second radiator including first and second ends, provided on the side of the first main surface, and coupled to the first radiator via a second interlayer conductor;

wherein

the wireless IC element is connected to the first end of the first radiator;

the first end of the second radiator is connected to the second end of the first radiator; and

the second end of the second radiator is not connected to the wireless IC element such that the second radiator is open.

2. The wireless IC device described in claim 1, wherein the feeding circuit is loop-shaped, and the loop-shaped feeding circuit is coupled to the first radiator via a direct current or via an electromagnetic field.

3. The wireless IC device described in claim 2, wherein the loop-shaped feeding circuit is coupled to the second radiator via an electromagnetic field.

4. The wireless IC device described in claim 2, wherein the loop-shaped feeding circuit includes a loop surface that is perpendicular or substantially perpendicular to the first radiator and the second radiator.

5. The wireless IC device described in claim 2, wherein the substrate is a child substrate mounted on a parent substrate, and the parent substrate is provided with an additional radiator coupled to the loop-shaped feeding circuit via an electromagnetic field.

6. The wireless IC device described in claim 1, wherein at least one of the first radiator and the second radiator is loop-shaped.

7. The wireless IC device described in claim 6, wherein at least one of the first radiator and the second radiator includes a portion including a slit.

8. The wireless IC device described in claim 1, wherein the first radiator has a solid configuration, and the second radiator is configured in a loop shape, and an area inside a loop of the second radiator includes a region in which the first radiator and the second radiator do not overlap each other in a plan view.

9. The wireless IC device described in claim 1, wherein a first ground electrode provided on the side of the second main surface of the substrate defines the first radiator, and a second ground electrode provided on the side of the first main surface of the substrate defines the second radiator.

10. The wireless IC device described in claim 1, wherein the wireless IC element is a wireless IC chip arranged to process a high-frequency signal.

11. The wireless IC device described in claim 1, wherein the wireless IC element includes a wireless IC chip arranged to process a high-frequency signal and a feeding circuit substrate which includes a feeding circuit having a predetermined resonant frequency.

12. The wireless IC device described in claim 1, wherein the first and second radiators define antennas or ground electrodes of electronic components.

13. The wireless IC device described in claim 1, wherein

the substrate is a multilayer substrate including base layers laminated on each other;

the first radiator is provided on a first of the base layers;

the second radiator is provided on a second of the base layers;

a third radiator is provided on a third of the base layers;

the first, second and third radiators are loop-shaped and direct-current-coupled to each other.

14. The wireless IC device described in claim 1, wherein the second radiator has a solid configuration, and the second radiator and the first radiator are direct-current-coupled by a plurality of the second interlayer conductors.

15. The wireless IC device described in claim 1, wherein the second radiator is loop-shaped and includes a slit provided in a portion spaced away from the feeding circuit.

16. The wireless IC device described in claim 1, wherein the substrate is a multilayer substrate including base layers laminated on each other;

the first radiator is provided on a first of the base layers;

the second radiator is provided on a second of the base layers located adjacent to feeding conductors of the feeding circuit;

a third of the base layers is laminated between the first of the base layers and the second of the base layers;

end portions of the feeding conductors are direct-current-coupled to opposite side portions of first end portions of the first radiator via the first interlayer conductor; and

the second radiator is loop-shaped and includes a slit, and portions of the second radiator facing the slit are direct-current-coupled to second end portions of the first radiator via the second interlayer conductor.

17. The wireless IC device described in claim 1, wherein

the feeding circuit includes the first interlayer conductor and first, second and third feeding conductors located adjacent to each other in plan view and connected to each other via the first interlayer conductor;

and

the feeding circuit is coupled to the first radiator only by electromagnetic field coupling.

18. The wireless IC device described in claim 1, wherein the second radiator is spaced away from first and second feeding conductors of the feeding circuit and the second radiator is coupled to the feeding circuit via the second interlayer conductor and the first radiator.

19. The wireless IC device described in claim 1, wherein the first main surface of the substrate includes a cavity, and the wireless IC element is located in the cavity partially or completely.

20. A radio frequency identification system comprising the wireless IC device according to claim 1.