Radio IC device and radio communication terminal

• US 9,336,475 B2
• Filed: 07/22/2014
• Issued: 05/10/2016
• Est. Priority Date: 04/25/2012
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Takeoka, Makoto, Dokai, Yuya, Murayama, Hiromi
• Primary Examiner(s): Mikels, Matthew
• Application Number:
  US14/337,547
• Publication Number:
  US 20140332594A1
• Time in Patent Office: 658 Days
• Field of Search: 235/435, 235/439, 235/451, 235/487, 235/492, 340/10, 340/572
• US Class Current: 1/1
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 19/07777 the antenna being of the inductive type
• 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 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them

Abstract

A radio IC device includes a radio IC element that includes an antenna terminal connected to an antenna element, and a ground terminal connected to a ground conductor provided integrally with the antenna element, and a circuit element that includes an impedance matching circuit connected to the antenna terminal of the radio IC element. The circuit element includes a first inductance element that defines the impedance matching circuit, and a second inductance element that is connected, as a high-frequency cutoff circuit for the radio IC element, to the ground terminal.

Claims

1. A radio IC device comprising:

a radio IC element including an antenna terminal connected to an antenna element, and a ground terminal connected to a ground conductor; and

a circuit board including a circuit element that includes an impedance matching circuit connected to the antenna terminal of the radio IC element;

wherein

a portion of the ground conductor defines the antenna element, and the antenna terminal of the radio IC element is connected to the ground conductor via the impedance matching circuit; and

the circuit board further includes an inductance element that is provided separately from the impedance matching circuit and that is connected, as a high-frequency cutoff circuit for the radio IC element, between the ground conductor and the ground terminal.

2. The radio IC device according to claim 1, wherein the circuit board is defined by a multilayer body including a plurality of stacked substrate layers.

3. The radio IC device according to claim 1, wherein the impedance matching circuit is defined by another inductance element, and the inductance element and the another inductance element are not coupled to each other or are substantially not coupled to each other.

4. The radio IC device according to claim 1, wherein the impedance matching circuit is defined by another inductance element, each of the inductance element and the another inductance element includes a coil, and winding axes of the coils of the inductance element and the another inductance element are arranged in different positions.

5. The radio IC device according to claim 1, wherein the impedance matching circuit is defined by another inductance element, each of the inductance element and the another inductance element includes a coil, and winding axes of the coils of the inductance element and the another inductance element do not overlap in a plan view.

6. A radio IC device comprising:

a radio IC element including an antenna terminal connected to an antenna element, and a wired connection terminal connected to a different IC element by a wire; and

a circuit board including a circuit element that includes an impedance matching circuit connected to the antenna terminal of the radio IC element;

wherein

the different IC element is connected to a ground conductor;

a portion of the ground conductor defines the antenna element, and the antenna terminal of the radio IC element is connected to the ground conductor via the impedance matching circuit; and

the circuit board further includes an inductance element that is provided separately from the impedance matching circuit and that is connected, as a high-frequency cutoff circuit for the radio IC element, between the different IC element and the wired connection terminal.

7. The radio IC device according to claim 6, wherein the circuit board is defined by a multilayer body including a plurality of stacked substrate layers.

8. The radio IC device according to claim 6, wherein the impedance matching circuit is defined by another inductance element, and the inductance element and the another inductance element are not coupled to each other or are substantially not coupled to each other.

9. The radio IC device according to claim 6, wherein the impedance matching circuit is defined by another inductance element, each of the inductance element and the another inductance element includes a coil, and winding axes of the coils of the inductance element and the another inductance element are arranged in different positions.

10. The radio IC device according to claim 6, wherein the impedance matching circuit is defined by another inductance element, each of the inductance element and the another inductance element includes a coil, and winding axes of the coils of the inductance element and the another inductance element do not overlap in a plan view.

11. The radio IC device according to claim 6, wherein the inductance element is connected to a ground electrode of the radio IC element.

12. The radio IC device according to claim 6, wherein the inductance element is connected to a power supply electrode of the radio IC element.

13. The radio IC device according to claim 6, wherein the inductance element is connected to a clock electrode of the radio IC element.

14. A radio communication terminal comprising:

a radio IC device; and

a mother board including a ground conductor and an antenna element;

wherein

the radio IC device includes a radio IC element that includes an antenna terminal connected to the antenna element and a wired connection terminal connected to a different IC element by a wire, and a circuit board including a circuit element that includes an impedance matching circuit connected to the antenna terminal of the radio IC element;

the different IC element is connected to the ground conductor;

a portion of the ground conductor defines the antenna element, and the antenna terminal of the radio IC element is connected to the ground conductor via the impedance matching circuit; and

the circuit board further includes an inductance element that is provided separately from the impedance matching circuit and that is connected, as a high-frequency cutoff circuit for the radio IC element, between the different IC element and the wired connection terminal.

15. The radio communication terminal according to claim 14, wherein the circuit board is defined by a multilayer body including a plurality of stacked substrate layers.

16. The radio communication terminal according to claim 14, wherein the inductance element is connected to a ground electrode of the radio IC element and the ground conductor.

17. The radio communication terminal according to claim 14, wherein the inductance element is connected to a power supply electrode of the radio IC element and a power supply element provided on the mother board.

18. The radio communication terminal according to claim 14, wherein the inductance element is connected to a clock electrode of the radio IC element and a host IC provided on the mother board.

19. The radio communication terminal according to claim 14, wherein the inductance element is connected to a data electrode of the radio IC element and a host IC provided on the mother board.

20. A radio communication terminal comprising:

a radio IC device; and

a mother board including a ground and an antenna element;

wherein

the radio IC device includes a radio IC element including an antenna terminal connected to an antenna element, a ground terminal connected to a ground conductor, and a circuit board including a circuit element that includes an impedance matching circuit connected to the antenna terminal of the radio IC element;

a portion of the ground conductor defines the antenna element, and the antenna terminal of the radio IC element is connected to the ground conductor via the impedance matching circuit;

wherein

the circuit board further includes an inductance element that is provided separately from the impedance matching circuit and that is connected, as a high-frequency cutoff circuit for the radio IC element, between the ground conductor and the ground terminal.