Radio IC device

• US 8,177,138 B2
• Filed: 04/06/2011
• Issued: 05/15/2012
• Est. Priority Date: 10/29/2008
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kato, Noboru, Ikemoto, Nobuo
• Primary Examiner(s): Le, Thien M.
• Assistant Examiner(s): MARSHALL, CHRISTLE I
• Application Number:
  US13/080,775
• Publication Number:
  US 20110186641A1
• Time in Patent Office: 405 Days
• Field of Search: 3405721- 8, 343/700
• US Class Current: 235/492
• 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: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• 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

Abstract

A radio IC device that is highly efficient in transmitting signals from a radio IC to a radiation pattern includes a radio IC chip arranged to processes radio signals, an auxiliary electrode pattern that is connected to the radio IC chip and includes a loop-shaped electrode, and a radiation electrode pattern that includes a magnetic-field radiation electrode having a resonant frequency and an electric-field radiation electrode having a resonant frequency. The loop-shaped electrode of the auxiliary electrode pattern is coupled to a maximum-voltage section of the magnetic-field radiation electrode through a capacitor.

Claims

1. A radio IC device comprising:

a radio IC arranged to process radio signals;

an auxiliary electrode pattern connected to the radio IC; and

a radiation electrode pattern coupled to the auxiliary electrode pattern and arranged to radiate the radio signals;

wherein

a portion of the auxiliary electrode pattern is coupled to a maximum-voltage section in the radiation electrode pattern through a capacitor.

2. The radio IC device according to claim 1, wherein the radiation electrode pattern is an antenna pattern including a magnetic-field radiation electrode having a predetermined resonant frequency f1 that is coupled to an electric-field radiation electrode that has a predetermined resonant frequency f2.

3. The radio IC device according to claim 2, wherein

the auxiliary electrode pattern includes a loop-shaped electrode provided on a first supporting body;

and

the radiation electrode pattern includes the magnetic-field radiation electrode and the electric-field radiation electrode provided on a second supporting body.

4. The radio IC device according to claim 3, wherein the first supporting body is attached to the second supporting body such that a portion of the loop-shaped electrode is coupled to a maximum-voltage section in the magnetic-field radiation electrode through a capacitor.

5. The radio IC device according to claim 4, wherein the loop-shaped electrode is arranged so as to electrically extend to both of the magnetic-field radiation electrode and the electric-field radiation electrode.

6. The radio IC device according to claim 5, wherein

the loop-shaped electrode includes a maximum-current section and a maximum-voltage section;

the maximum-current section of the loop-shaped electrode is coupled to a maximum-current section of the electric-field radiation electrode through a magnetic field; and

the maximum-voltage section of the loop-shaped electrode is capacitively coupled to the maximum-voltage section of the magnetic-field radiation electrode.

7. The radio IC device according to claim 1, wherein the radio IC is connected to the auxiliary electrode pattern through a feeder circuit board that includes a feeder circuit including at least one coil pattern.

8. The radio IC device according to claim 7, wherein

the feeder circuit has a predetermined resonant frequency;

and

a frequency of the radio signal substantially corresponds to the predetermined resonant frequency of the feeder circuit.