Low-frequency tag with separate transmit and receive antennas

• US 8,514,141 B2
• Filed: 04/13/2010
• Issued: 08/20/2013
• Est. Priority Date: 04/13/2009
• Status: Active Grant

• Current Assignee: Visible Assets Incorporated (NOV, Inc.)
• Original Assignee: Visible Assets Incorporated (NOV, Inc.)
• Inventors: August, M. Jason, Stevens, John K., Waterhouse, Paul
• Primary Examiner(s): PHAN, THO GIA
• Application Number:
  US12/759,542
• Publication Number:
  US 20100259459A1
• Time in Patent Office: 1,225 Days
• Field of Search: 343/787, 343/788, 340/572.7
• US Class Current: 343/787
• 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 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• 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

Abstract

A low frequency inductive two-way radio transceiver tag is provided that has separate antennas for transmitting and receiving signals within a reading volume. Thus, the tag of the invention includes both a transmit antenna and a receiving antenna, either separately or as a single antenna tuneable between two functional states with different impedances. The impedance of the receiving antenna is greater than the impedance of the transmitting antenna. For example, the impedance of the receiving antenna may be greater than the impedance of the transmitting antenna by a factor of 10³.

Claims

1. A two-way low frequency inductive two-way radio transceiver tag, wherein the tag comprises a transmit antenna and a separate receiving antenna, and wherein the impedance of the receiving antenna is greater than the impedance of the transmitting antenna by a factor of 10³.

2. The transceiver tag of claim 1, wherein the transmit and receiving antennas are ferrite antennas.

3. The transceiver tag of claim 1, wherein the transmit and receiving antennas are ferrite antennas.

4. The transceiver tag of claim 1, wherein a single antenna structure is used for both the transmit and receive antennas, and the impedance of the antenna structure is tuned in accordance with the function.

5. A system comprising:

(a) a read antenna effective to transmit signals to and receive signals from a low frequency inductive two-way radio transceiver tag, and

(b) one or more two-way low frequency inductive two-way radio transceiver tag, wherein the tag comprises a transmit antenna, and a separate receiving antenna, and wherein the impedance of the receiving antenna is greater than the impedance of the transmitting antenna by a factor of 10³.

6. The system of claim 5, wherein the transmit and receiving antennas are ferrite antennas.

7. The system of claim 5, comprising a single read antenna, wherein the read antenna is in a room at the floor or ceiling of the room, and wherein the tags can be read at any location within the volume of the room.

8. The system of claim 5, wherein a single antenna structure is used for both the both the transmit and receive antennas of the tag, and the impedance of the antenna structure is tuned in accordance with the function.

9. The system of claim 8, wherein the transmit and receiving antennas are ferrite antennas.

10. The system of claim 8, comprising a single read antenna, wherein the read antenna is in a room at the floor or ceiling of the room, and wherein the tags can be read at any location within the volume of the room.