Wireless communication device and metal article

• US 8,336,786 B2
• Filed: 03/26/2012
• Issued: 12/25/2012
• Est. Priority Date: 03/12/2010
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kato, Noboru, Shiroki, Koji
• Primary Examiner(s): VO, TUYEN KIM
• Application Number:
  US13/429,465
• Publication Number:
  US 20120187198A1
• Time in Patent Office: 274 Days
• Field of Search: 235/375, 235/451, 235/486, 235/487, 235/492, 340/10.1, 340/10.2, 340/572.1, 340/572.2, 340/572.7
• US Class Current: 235/492
• CPC Class Codes: G06K 19/07771 the record carrier comprising means for minimising adverse effects on the data communication capability of the record carrier, e.g. minimising Eddy currents induced in a proximate metal or otherwise electromagnetically interfering object
• CPC Class Codes: G06K 19/07773 Antenna details antennas for wireless devices, e.g. RFID tags, in general H01Q1/22
• CPC Class Codes: G06K 19/07775 the antenna being on-chip
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• 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 1/48 Earthing means; Earth screens; Counterpoises
• 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: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

A wireless communication device includes a wireless IC device, a dielectric substrate, and a metal plate. A radiation conductor coupled to the wireless IC device is provided on the front surface of the dielectric substrate, and a ground conductor connected to the radiation conductor through an interlayer connection conductor is provided on a back surface. The dielectric substrate is fixed to the metal plate via an insulating adhesive, and is crimped by a conductive member. The front and back surfaces of the metal plate are electrically connected to each other by the conductive member, and when a high-frequency signal is supplied from the wireless IC device, a high-frequency signal current on the front surface side of the metal plate is conducted to the back surface side of the metal plate through a surface boundary portion between the conductive member and the metal plate, and radiated as a high-frequency signal.

Claims

1. A wireless communication device comprising:

a wireless IC device configured to process a high-frequency signal;

a radiation conductor coupled to the wireless IC device;

a ground conductor connected to the radiation conductor; and

a metal plate including first and second main surfaces arranged such that the ground conductor is coupled to the first main surface and a portion that defines a radiation element;

wherein

the metal plate includes a current path portion arranged to conduct a high-frequency signal current on a first main surface side to a second main surface side of the metal plate when a high-frequency signal is supplied from the wireless IC device through the radiation conductor and the ground conductor; and

a conductive member electrically conducting the first main surface and the second main surface of the metal plate to each other is provided in the metal plate; and

the current path portion is located in a surface boundary portion between the conductive member and the metal plate.

2. The wireless communication device according to claim 1, wherein the radiation conductor is provided on a first main surface of a dielectric substrate, and includes a power feeding portion connected to the wireless IC device, and the radiation conductor and the ground conductor are connected to each other through an interlayer connection conductor.

3. The wireless communication device according to claim 2, further comprising:

a loop-shaped electrode including the radiation conductor, the ground conductor, and the interlayer connection conductor arranged to extend from the power feeding portion;

wherein

a loop plane of the loop-shaped electrode is disposed so as to be perpendicular or substantially perpendicular to the first main surface of the metal plate.

4. The wireless communication device according to claim 1, wherein the conductive member is electrically connected to the ground conductor.

5. The wireless communication device according to claim 1, further comprising:

a through hole provided in the metal plate and penetrating through the first main surface and the second main surface of the metal plate;

wherein

the current path portion is provided in a peripheral surface portion of the through hole.

6. The wireless communication device according to claim 1, wherein the wireless IC device is a wireless IC chip arranged to process a high-frequency signal.

7. The wireless communication device according to claim 1, wherein the wireless IC device includes a wireless IC chip arranged to process a high-frequency signal and a feed circuit substrate including a feed circuit that has a predetermined resonance frequency.

8. A metal article comprising:

a wireless communication device; and

a metal plate;

wherein

the wireless communication device includes;

a wireless IC device configured to process a high-frequency signal;

a radiation conductor coupled to the wireless IC device, and

a ground conductor connected to the radiation conductor;

wherein

the metal plate includes a current path portion arranged to conduct a high-frequency signal current on a first main surface side to a second main surface side of the metal plate when a high-frequency signal is supplied from the wireless IC device through the radiation conductor and the ground conductor; and

a conductive member electrically conducting the first main surface and the second main surface of the metal plate to each other is provided in the metal plate; and

the current path portion is located in a surface boundary portion between the conductive member and the metal plate.