Antenna and wireless IC device

• US 8,917,211 B2
• Filed: 02/18/2014
• Issued: 12/23/2014
• Est. Priority Date: 11/17/2008
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kato, Noboru, Dokai, Yuya
• Primary Examiner(s): TRAIL, ALLYSON NEEL
• Application Number:
  US14/182,339
• Publication Number:
  US 20140159984A1
• Time in Patent Office: 308 Days
• Field of Search: 343/700, 343/843, 343/850, 340/10.1
• US Class Current: 343/700.MS
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/0775 arrangements for connecting the integrated circuit to the antenna
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• 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 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 1/40 Radiating elements coated with or embedded in protective material
• 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 9/045 with particular feeding means for circular polarisation H01Q9/0428

Abstract

An antenna and a wireless IC device that includes the antenna are provided for which the manufacturing process is simple and for which there is a low probability of a poor connection occurring between a feeder portion and a radiation electrode. An antenna includes a radiation electrode that is provided on a main surface of an insulator board, a ground electrode and/or a counter electrode that is arranged so as to oppose the radiation electrode, and a magnetic field electrode that is connected to the radiation electrode through a connection portion. The magnetic field electrode is defined by line-shaped electrodes and feeds a signal to the radiation electrode from a feeder portion defined by ends of the line-shaped electrodes through the magnetic field electrode.

Claims

1. A wireless communication apparatus comprising:

a wireless IC including first and second terminals;

a planar radiation electrode including an opening and a slit extending from the opening to an edge portion of the radiation electrode; and

first and second feeder portions respectively connected to the radiation electrode at first and second sides of the slit;

wherein

an inner peripheral edge portion of the opening defines a magnetic field electrode; and

the first and second terminals of the wireless IC are respectively connected to the first and second feeder portions such that the magnetic field electrode is connected in parallel to the wireless IC.

2. The wireless communication apparatus according to claim 1, wherein the first and second terminals of the wireless IC are respectively connected to the first and second feeder portions via capacitances.

3. The wireless communication apparatus according to claim 1, wherein at least one of the first and second feeder portions projects into the opening.

4. The wireless communication apparatus according to claim 3, wherein both of the first and second feeder portions project into the opening.

5. The wireless communication apparatus according to claim 1, wherein the first and second feeder portions oppose each other with the slit therebetween.

6. The wireless communication apparatus according to claim 1, wherein the opening has a circular or substantially circular shape.

7. The wireless communication apparatus according to claim 1, wherein the opening has an elliptical or substantially elliptical shape.

8. The wireless communication apparatus according to claim 1, further comprising:

an insulator board;

wherein

the radiation electrode is provided on a first main surface of the insulator board.

9. The wireless communication apparatus according to claim 8, further comprising a ground electrode arranged on a second main surface of the insulator board.

10. The wireless communication apparatus according to claim 9, wherein the ground electrode is a metal plate.

11. The wireless communication apparatus according to claim 8, further comprising a counter electrode arranged on a second main surface of the insulator board.

12. The wireless communication apparatus according to claim 11, further comprising a ground electrode arranged so as to oppose the counter electrode.

13. The wireless communication apparatus according to claim 12, wherein the counter electrode and the ground electrode are coupled with each other through a capacitance.

14. The wireless communication apparatus to claim 12, wherein the counter electrode and the ground electrode are in direct conductive contact with each other.

15. The wireless communication apparatus according to claim 11, wherein the radiation electrode and the counter electrode are in direct conductive contact with each other through end portions thereof.

16. The wireless communication apparatus according to claim 1, wherein the radiation electrode has a longitudinal dimension and a width dimension, and an electrode length of the radiation electrode extending along in the longitudinal dimension corresponds to an electrical length of substantially ½

a wavelength of a frequency band of signals to be transmitted and received.

17. The wireless communication apparatus according to claim 8, wherein the insulator board is made of an injection molded resin.