RFID tag and manufacturing method thereof

• US 20080036673A1
• Filed: 07/31/2007
• Published: 02/14/2008
• Est. Priority Date: 08/09/2006
• Status: Active Grant

• Current Assignee: Fujitsu Frontech Limited (Fujitsu Limited), Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Sugimura, Yoshiyasu, Kai, Manabu, Baba, Shunji, Maniwa, Toru, Yamagajo, Takashi, Oishi, Yasuyuki
• Granted Patent: US 8,022,878 B2
• Time in Patent Office: Days
• US Class Current: 343/793
• 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 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 9/0457 electromagnetically coupled to the feed line
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

An RFID tag having a tag antenna and an LSI chip, comprising: a power-supply pattern on which the LSI chip is mounted; a patch antenna that functions as the tag antenna; and a high-frequency connection section that makes a high-frequency connection between the power-supply pattern and the patch antenna. The high-frequency connection section is formed, for example, by forming a slot in the patch antenna, layering one end of a small dipole antenna that functions as the power-supply pattern over the slot so that it crosses over the slot, and supplying power from the small dipole antenna to the patch antenna.

Claims

1. An RFID tag having a tag antenna and an LSI chip, comprising:

a power-supply pattern on which the LSI chip is mounted;

a patch antenna that functions as the tag antenna; and

an high-frequency connection section that makes a high-frequency connection between said power-supply pattern and said patch antenna.

2. The RFID tag of claim 1 further comprising:

a dielectric member having said power-supply pattern, patch antenna and high-frequency connection section formed on one side, and a conductive pattern that functions as ground formed on the other side; and

a short-circuit unit that forms a short circuit between one edge of the patch antenna and ground on the side surface of the dielectric member.

3. The RFID tag of claim 1 that comprises a linear antenna pattern that functions as the power-supply pattern.

4. The RFID tag of claim 1 that comprises a loop pattern that functions as the power-supply pattern.

5. The RFID tag of claim 3, wherein

a slot is formed in said patch antenna, and one end of a small dipole antenna as said linear antenna is layered over the slot so that it crosses over the slot, and power is supplied from the small dipole antenna to the patch antenna.

6. The RFID tag of claim 3, wherein

a cutout section is formed in said patch antenna, one end of a small dipole antenna as said linear antenna is high-frequency connected with the cutout section, and power is supplied from the small dipole antenna to the patch antenna.

7. The RFID tag of claim 5, wherein

said LSI chip is mounted in the center of said small dipole antenna, and another patch antenna (second patch antenna) is placed so that it has left-right symmetry with said patch antenna (first patch antenna) with said LSI chip being in the center;

and

the positional relationship between said first patch antenna and one end of said small dipole antenna, and the positional relationship between the second patch antenna and other end of said dipole antenna are the same.

8. The RFID tag of claim 5, wherein

a loop pattern that functions as a parallel inductor is connected to said small dipole antenna.

9. The RFID tag of claim 3, further comprising

a loop pattern that functions as a parallel inductor;

wherein

said LSI chip is mounted in the middle of the loop pattern,

a monopole antenna is formed that connects the end section of that loop pattern with the end section of the linear antenna section, and

power is supplied from the monopole antenna to the patch antenna.

10. A manufacturing method for an RFID tag having a tag antenna and an LSI chip, comprising steps of:

forming a power-supply pattern on which an LSI chip is mounted, and a patch antenna that functions as a tag antenna on the surface of a double-sided print board by etching, so that the power-supply pattern and tag antenna are high-frequency connected;

making a conductive pattern on the rear surface of said print board ground; and

mounting said LSI chip on said power-supply pattern to create said RFID tag.

11. A manufacturing method for an RFID tag having a tag antenna and an LSI chip, comprising steps of:

forming a power-supply pattern on which an LSI chip is mounted, and a patch antenna that functions as a tag antenna on an insulating film by printing or etching, so that the power-supply pattern and tag antenna are high-frequency connected;

mounting said LSI chip on said power-supply pattern;

attaching the insulating film on top of a single-sided print board; and

making a conductive pattern on the rear surface of the print board ground.

12. A manufacturing method for an RFID tag having a tag antenna and an LSI chip, comprising steps of:

forming a power-supply pattern on which an LSI chip is mounted on an insulating film by printing or etching;

mounting said LSI chip on said power-supply pattern;

forming a patch antenna that functions as a tag antenna on the surface of a double-sided print board by etching;

making a conductive pattern on the rear surface of said print board ground; and

attaching the insulating film on to the surface of said print board to create the RFID tag.

13. A manufacturing method for an RFID tag having a tag antenna and an LSI chip, comprising steps of:

forming a patch antenna that functions as a tag antenna on an insulating film by printing or etching;

forming a power-supply pattern on which an LSI chip is mounted on the surface of a double-sided print board by etching;

making a conductive pattern on the rear surface of said print board ground;

mounting said LSI chip on said power-supply pattern; and

attaching the insulating film to the surface of said print board to create the RFID tag.