WIRELESS IC DEVICE

• US 20110181486A1
• Filed: 04/06/2011
• Published: 07/28/2011
• Est. Priority Date: 10/24/2008
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: KATO, Noboru
• Granted Patent: US 9,231,305 B2
• Time in Patent Office: Days
• US Class Current: 343/850
• 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 7/06 with core of ferromagnetic material H01Q7/02 takes precedence

Abstract

A wireless IC device has a resonant frequency that is hardly altered or affected by external influences and reliably communicates with a reader/writer. The wireless IC device includes a wireless IC chip arranged to process a radio signal, a feeder circuit board coupled to the wireless IC chip and including a feeder circuit, and a radiation electrode arranged at least one principal surface of the feeder circuit board. The feeder circuit board includes a magnetic material and has the feeder circuit disposed therein. The radiation electrode is disposed on at least one principal surface of the feeder circuit board so as to be electromagnetically coupled to the feeder circuit and includes at least two open ends. The wireless IC chip is coupled to the radiation electrode through the feeder circuit and communicates with a reader/writer using HF band frequency.

Claims

1. A wireless IC device, comprising:

a wireless IC arranged to process a radio signal;

a feeder circuit board coupled to the wireless IC and including a feeder circuit that includes an inductance element, the feeder circuit board including a magnetic material; and

a radiation electrode disposed on at least one principal surface of the feeder circuit board so as to be electromagnetically coupled to the feeder circuit, the radiation electrode including at least two adjacent open ends.

2. The wireless IC device according to claim 1, wherein the radiation electrode is arranged on two opposing principal surfaces of the feeder circuit board.

3. The wireless IC device according to claim 1, wherein the radiation electrode is a cutout loop electrode including the open ends.

4. The wireless IC device according to claim 1, wherein the radiation electrode is arranged to overlap the feeder circuit provided in the feeder circuit board in plan view.

5. The wireless IC device according to claim 1, wherein the radiation electrode is arranged at a marginal portion of the principal surface of the feeder circuit board.

6. The wireless IC device according to claim 1, wherein the radiation electrode is covered with a non-magnetic material layer.

7. The wireless IC device according to claim 1, wherein resonant frequency of the radiation electrode is higher than resonant frequency of the feeder circuit.

8. The wireless IC device according to claim 1, wherein the wireless IC is arranged inside the radiation electrode.

9. The wireless IC device according to claim 1, further comprising a radiation plate electromagnetically coupled to the radiation electrode.