ANTENNA DEVICE AND CARD-SHAPED STORAGE MEDIUM

• US 20020096568A1
• Filed: 11/23/1999
• Published: 07/25/2002
• Est. Priority Date: 11/30/1998
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: ARISAWA, SHIGERU
• Granted Patent: US 6,626,363 B2
• Time in Patent Office: Days
• US Class Current: 235/492
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0715 the arrangement including means to regulate power transfer to the integrated circuit
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs

Abstract

An antenna device can operate a connected electronic circuit always efficiently and normally. The antenna device for supplying a predetermined electronic circuit with electromotive force based on the energy of electromagnetic waves received via the antenna comprises a load resistance conversion means for converting the load resistance of the electronic circuit from the viewpoint of the antenna into a predetermined value, and the load resistance conversion means supplies the electronic circuit with the maximum electromotive force.

Claims

1. An antenna device for supplying a predetermined electronic circuit with electromotive force based on the energy of electromagnetic waves received via the antenna, comprising

load resistance conversion means for converting the load resistance of said electronic circuit from the viewpoint of the antenna into a predetermined value, wherein

said load resistance conversion means supplies said electronic circuit with the maximum of the electromotive force.

2. The antenna device according to claim 1, further comprising

resonant means for improving reception efficiency by resonating with the electromagnetic waves.

3. The antenna device according to claim 1, wherein

said load resistance conversion means converts the load resistance of said electronic circuit into a predetermined value in accordance with the distance to an electromagnetic waves emitting means disposed at a position opposite said antenna.

4. The antenna device according to claim 1, wherein

said load resistance conversion means comprises a transformer.

5. The antenna device according to claim 1, wherein

said load resistance conversion means comprises a loop coil.

6. The antenna device according to claim 1, wherein

said load resistance conversion means comprises inductance and capacitance.

7. A card-shaped storage medium for writing/reading data to/from a predetermined electronic circuit via electromagnetic waves in non-contact, comprising:

an antenna for receiving said electromagnetic waves and supplying a predetermined electronic circuit with electromotive force based on energy of the electromagnetic waves; and

load resistance conversion means for converting the load resistance of said electronic circuit from the viewpoint of said antenna into a predetermined value, wherein

said load resistance conversion means supplies said electronic circuit with the maximum of said electromotive force.

8. The card-shaped storage medium according to claim 7, further comprising

a resonant means to improve reception efficiency by resonating with electromagnetic waves.

9. The card-shaped storage medium according to claim 7, wherein

said load resistance conversion means converts the load resistance of said electronic circuit into a predetermined value in accordance with the distance to an electromagnetic waves emitting means disposed at a position opposite said antenna.

10. The card-shaped storage medium according to claim 7, wherein

said load resistance conversion means comprises a transformer.

11. The card-shaped storage medium according to claim 7, wherein

said load resistance conversion means comprises a loop coil.

12. The card-shaped storage medium according to claim 7, wherein

said load resistance conversion means comprises inductance and capacitance.