Electronic device, method and system for half duplex data transmission

• US 9,179,492 B2
• Filed: 10/26/2011
• Issued: 11/03/2015
• Est. Priority Date: 10/26/2011
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments Deutschland Gesellschaft Mit Beschrã¤Nkter Haftung (Texas Instruments, Inc.), Texas Instruments, Inc.
• Inventors: Meier, Herbert, Hagl, Andreas, Childers, Jim
• Primary Examiner(s): Tweel, Jr., John A
• Assistant Examiner(s): Aziz, Adnan
• Application Number:
  US13/282,076
• Publication Number:
  US 20130107762A1
• Time in Patent Office: 1,469 Days
• Field of Search: 340/572.5, 340/5.61
• US Class Current: 1/1
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G06K 19/0724 the arrangement being a circuit for communicating at a plurality of frequencies, e.g. for managing time multiplexed communication over at least two antennas of different types
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 19/07792 the antenna adapted for extending in three dimensions
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications
• CPC Class Codes: G07C 2009/00198 the keyless data carrier having more than one limited data transmission ranges
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04L 5/16 Half-duplex systems; Simplex/duplex switching; Transmission of break signals non-automatically inverting the direction of transmission
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation

Abstract

An electronic device and method for half duplex data transmission in a long range keyless entry and go system, and more specifically to an RFID transponder, a corresponding read/write (R/W) unit and methods for operating the RFID transponder and the R/W-unit. There is a first coil, a second coil and a third coil, being arranged as a three-dimensional antenna, a first capacitor, a second capacitor and a third capacitor couplable in parallel to the first coil, the second coil and the third coil, respectively, for selectively forming a first, a second and a third parallel-resonant circuit for receiving radio signals, a series-resonant circuit for transmitting radio signals and a control stage configured to either use one of the first, second or third parallel-resonant circuits for receiving radio signals or the series-resonant circuit for transmitting signals.

Claims

1. An electronic device for half-duplex near field transmission of radio signals comprising:

a first coil, a second coil and a third coil, being arranged as a three-dimensional antenna each of the coils operating independently of the other;

a first capacitor, a second capacitor and a third capacitor coupleable in parallel to the first coil, the second coil and the third coil, respectively, for selectively forming a first, a second and a third parallel-resonant circuit for transmitting and receiving radio signals;

first, second, third series-resonant circuits for transmitting near field radio signals formed by fourth, fifth and sixth capacitors in series with the first, second and third coils, respectively; and

a control stage configured to either use one of the first, second or third parallel-resonant circuits for receiving radio signals and for charging a capacitor to power the electronic device and utilizing a corresponding one of the first, second, third series-resonant circuits for transmitting near field signals.

2. The electronic device according to claim 1, wherein the series-resonant circuit is configured to transmit radio signals in the same frequency range as the parallel-resonant circuits.

3. The electronic device according to claim 2, wherein each of the parallel-resonant circuits is configured to receive the radio signals at a first frequency, and the series-resonant circuit is configured to transmit the radio signals at the first frequency and a second frequency according to frequency shift keying.

4. The electronic device according to claim 1, wherein the fourth capacitor is coupled with a first side to a first side of the first coil for selectively forming the series-resonant circuit and for transmitting the radio signals through the first coil and the control stage is configured to switch from parallel resonance to serial resonance using either the first or the second frequency.

5. The electronic device according to claim 4, wherein the fifth capacitor is coupled with a first side to a first side of the second coil for selectively forming the series-resonant circuit and for transmitting the radio signals through the second coil and the control stage is configured to switch from parallel resonance to serial resonance using either the first or the second frequency.

6. The electronic device according to claim 5, wherein the sixth capacitor is coupled with a first side to a first side of the third coil for selectively forming the series-resonant circuit and for transmitting the radio signals through the third coil and the control stage is configured to switch from parallel resonance to serial resonance using either the first or the second frequency.

7. The electronic device according to claim 4, further comprising a seventh capacitor which is coupled with a first side to the first coil and with a second side to a first side of a switch that is coupled with a second side to ground for selectively changing the resonant frequency of the series-resonant circuit comprising the first coil and the fourth capacitor during transmission of the radio signals for frequency shift keying of the radio signal.

8. The electronic device according to claim 5, further comprising a seventh capacitor which is coupled with a first side to the first coil and with a second side to a first side of a switch that is coupled with a second side to ground for selectively changing the resonant frequency of the series-resonant circuit comprising the first coil and the fourth capacitor during transmission of the radio signals for frequency shift keying of the radio signal.

9. The electronic device according to claim 6, further comprising a seventh capacitor which is coupled with a first side to the first coil and with a second side to a first side of a switch that is coupled with a second side to ground for selectively changing the resonant frequency of the series-resonant circuit comprising the first coil and the fourth capacitor during transmission of the radio signals for frequency shift keying of the radio signal.

10. The electronic device according to claim 4, further comprising a first normally closed switch that is coupled between the first side of the first coil and a first side of the first capacitor so as to selectively decouple the first side of the first coil from the first side of the first capacitor.

11. The electronic device according to claim 5, further comprising a first normally closed switch that is coupled between the first side of the first coil and a first side of the first capacitor so as to selectively decouple the first side of the first coil from the first side of the first capacitor.

12. The electronic device according to claim 6, further comprising a first normally closed switch that is coupled between the first side of the first coil and a first side of the first capacitor so as to selectively decouple the first side of the first coil from the first side of the first capacitor.

13. The electronic device according to claim 7, further comprising a first normally closed switch that is coupled between the first side of the first coil and a first side of the first capacitor so as to selectively decouple the first side of the first coil from the first side of the first capacitor.

14. The electronic device according to claim 10, further comprising a second normally closed switch that is coupled between the first side of the second coil and a first side of the second capacitor so as to selectively decouple the first side second coil from the first side of the second capacitor.

15. The electronic device according to claim 14, further comprising a third normal-on switch that is coupled between the first side of the third coil and a first side of the third capacitor so as to selectively decouple the first side of the third coil from the first side of the third capacitor.

16. The electronic device according to claim 10, wherein the second sides of the first, second and third coil are coupled together and the second sides of the first, second and/or third capacitor are coupled together.

17. The electronic device according to claim 1, wherein the series-resonant circuit comprises a coil and a capacitor, and wherein the capacitor is coupled with a first side to a first side of the coil and with a second side to a switching stage that is configured to selectively couple the second side of the capacitor to a first supply voltage node having a first supply voltage level or a second supply voltage node having a second supply voltage level, in particular ground.

18. The electronic device according to claim 17, wherein the switching stage comprises a first transistor that is coupled with a first side of its channel to the second side of the capacitor and with a second side of its channel to the first supply voltage node and a second transistor that is coupled with a first side of its channel to the second side of the capacitor and with a second side of its channel to the second supply voltage node, so as to alternately and selectively switch the second side of the capacitor between the first supply voltage level and the second supply voltage level.

19. The electronic device according to claim 18, further comprising another capacitor that is coupled with a first side to the first side of the coil and with a second side to a switch for selectively coupling the second side of the capacitor to the second supply voltage level, in particular to ground.

20. A method for half-duplex transmission of radio signals comprising:

receiving radio signals in one of a first, second, and third coil being arranged as a three-dimensional antenna in a parallel-resonant circuit for providing power to electronic circuit each of the coils operating independently of the other;

selecting one of the first, second, third parallel-resonant circuits having greatest received signal strength indication (RSSI) for reception of radio signals;

transmitting near field radio signals with a corresponding one of the first, second, third series-resonant circuits formed by fourth, fifth and sixth capacitors in series with the first, second and third coils, respectively;

wherein each of the series-resonant circuits and parallel-resonant circuits are comprised in the same electronic device; and

wherein transmitting of the radio signals is performed according to frequency shift keying; and

switching between the parallel-resonant circuit and the series-resonant circuit.