Antenna for radio frequency identification systems

• US 20080042846A1
• Filed: 08/08/2006
• Published: 02/21/2008
• Est. Priority Date: 08/08/2006
• Status: Abandoned Application

• Current Assignee: Cobham Defense Electronic Systems Corporation (Cobham PLC), Sensormatic Electronics Corporation (Johnson Controls International plc)
• Original Assignee: Sensormatic Electronics Corporation (Johnson Controls International plc), M/A Com
• Inventors: Lanteri, Jean Pierre, Relihan, Timothy Joseph, Jenkins, Alan Peter, Shafer, Gary Mark, Carrez, Frederic
• Application Number:
  US11/500,817
• Publication Number:
  US 20080042846A1
• Time in Patent Office: Days
• US Class Current: 340/572.7
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• 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 1/38 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 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/26 Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• CPC Class Codes: H01Q 9/0435 using two feed points

Abstract

An antenna for a radio frequency identification (RFID) system and a method for communicating in an RFID system are provided. The antenna includes a first port configured to provide RFID communication in a first polarization plane and a second port configured to provide RFID communication in a second polarization plane. The first polarization plane is orthogonal to the second polarization plane.

Claims

1. An antenna for a radio frequency identification (RFID) system, the antenna comprising:

a first port configured to provide RFID communication in a first polarization plane; and

a second port configured to provide RFID communication in a second polarization plane, the first polarization plane orthogonal to the second polarization plane.

2. An antenna in accordance with claim 1 wherein the first polarization plane comprises horizontal polarization and the second polarization plane comprises vertical polarization.

3. An antenna in accordance with claim 1 wherein the first and second ports are configured to connect to at least one of an RFID transmitter and an RFID receiver of an RFID reader.

4. An antenna in accordance with claim 1 wherein the RFID communication comprises communication with at least one of a passive RFID tag and an active RFID tag.

5. An antenna in accordance with claim 1 wherein the first polarization plane and the second polarization plane define a linear cross-polarization.

6. An antenna in accordance with claim 1 wherein the first port and the second port are formed as part of one of a patch type antenna structure and a dipole antenna structure.

7. An antenna in accordance with claim 1 further comprising a two-dimensional resonator with a first side of the two-dimensional resonator connected to the first port and a second side of the two-dimensional resonator connected to the second port.

8. An antenna in accordance with claim 1 wherein the first and second ports are configured to be switched to each provide a transmit operation and a receive operation.

9. An antenna in accordance with claim 1 further comprising a first set of radiating antenna elements.

10. An antenna in accordance with claim 9 wherein the first set of radiating antenna elements comprises orthogonal antenna elements.

11. An antenna in accordance with claim 9 further comprising a second set of radiating antenna elements offset from the first set of radiating antenna elements.

12. An antenna in accordance with claim 11 wherein the second set of radiating antenna elements comprises orthogonal antenna elements.

13. An antenna in accordance with claim 11 wherein the first set of radiating antenna elements are offset from the second set of radiating antenna elements by an angle of about forty-five degrees.

14. An antenna in accordance with claim 11 further comprising a third port and a fourth port and wherein a first antenna element of the second set of radiating antenna elements is connected to the third port and a second antenna element of the second set of radiating antenna elements is connected to the fourth port.

15. A radio frequency identification (RFID) reader comprising:

a transmitting portion configured to transmit RFID signals;

a receiving portion configured to received RFID signals from at least one RFID tag; and

a dual port polarized antenna configured having orthogonal polarization and configured to be connected to the transmitting portion and the receiving portion.

16. An RFID reader in accordance with claim 15 wherein the dual port polarized antenna comprises a patch type antenna having a first set of orthogonal radiating antenna elements.

17. An RFID reader in accordance with claim 16 wherein the dual port polarized antenna comprises a second set of orthogonal radiating antenna elements offset by an angle from the first set of orthogonal radiating antenna elements.

18. An RFID reader in accordance with claim 15 further comprising a switch configured to switch connection of at least one of the transmitting portion and the receiving portion between a first port and a second port of the dual port polarized antenna.

19. An RFID reader in accordance with claim 15 further comprising a handheld housing having the transmitting portion, receiving portion and dual port polarized antenna therein.

20. A method for communicating in a radio frequency identification (RFID) system, the method comprising:

transmitting an RFID signal in a first polarization plane; and

receiving an RFID signal from an RFID tag in a second polarization plane, the first polarization plane orthogonal to the second polarization plane.