Radio frequency (RF) transponder (Tag) with composite antenna

• US 6,271,793 B1
• Filed: 11/05/1999
• Issued: 08/07/2001
• Est. Priority Date: 11/05/1999
• Status: Expired due to Term

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Brady, Michael John, Saraf, Ravi, Rubino, Judy
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US09/435,172
• Time in Patent Office: 641 Days
• Field of Search: H01/Q.138, 343/700.MS, 343/873, 296/00, 257/673, 257/666, 257/674, 257/735, 257/737
• US Class Current: 343/700.0MS
• 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 2924/01079 Gold [Au]
• 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 1/364 using a particular conducting material, e.g. superconductor
• 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
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making
• CPC Class Codes: Y10T 29/49144 by metal fusion
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

An antenna composed of composite material which can be screen printed is proposed for RFID transponders and other RF communication systems.

Claims

1. An apparatus comprising:

electrical circuitry; and

an antenna electrically connected with the electrical circuitry, the antenna for communicating radio frequency signals with a base station, the antenna comprising;

a composite material comprising electrically conducting particles mixed in a polymer material, wherein the composite material has a resistivity having a predetermined value low enough that the radio frequency signals activate the electrical circuitry.

2. The apparatus of claim 1, wherein the electrical circuitry comprises a semiconductor chip.

3. The apparatus of claim 2, wherein the semiconductor chip comprises electrically conducting pads which are in direct electrical contact to the composite material.

4. The apparatus of claim 2, wherein the semiconductor chip comprises electrically conducting pads which are in wire bonded electrical contact to the composite material.

5. The apparatus of claim 2, wherein the semiconductor chip comprises electrically conducting pads which are in wire bonded electrical contact to a metal pad which is in direct electrical contact with the composite material.

6. The apparatus of claim 2, wherein the semiconductor chip comprises metal bumps which are in direct electrical contact to the composite material.

7. The apparatus of claim 1, wherein the electrically conducting particles are metal.

8. The apparatus of claim 7, wherein the electrically conducting particles are silver.

9. The apparatus of claim 7, wherein the electrically conducting particles are copper coated with silver.

10. The apparatus of claim 7, wherein the electrically conducting particles are copper coated with gold.

11. The apparatus of claim 1, wherein the polymer material is an elastomer.

12. The apparatus of claim 1, wherein the polymer material is thermoplastic.

13. The apparatus of claim 12, wherein the electrically conductive particles occupy at least 30% by volume of the composite material.

14. The apparatus of claim 1, wherein the electrically conducting particles are electrically conducting polymeric particles.

15. The apparatus of claim 1, wherein the resistivity of the composite material is in the range from about 10 micro-ohm-cm to about 40 micro-ohm-cm.

16. The apparatus of claim 1, wherein the antenna is flexible.

17. The apparatus of claim 1, wherein the antenna and the electrical circuitry are attached to a substrate.

18. The apparatus of claim 17, wherein the substrate is a flexible substrate.

19. The apparatus of claim 17, further comprising a battery electrically attached to the electrical circuitry.