Radio-frequency identification transponder and method for data transmission by means of radio-frequency identification technology

Patent metadata

Field	Value
Publication number	US-10608705-B2
Application number	US-201916435815-A
Country	US
Kind code	B2
Filing date	Jun 10, 2019
Priority date	Jul 21, 2015
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

An RFID transponder includes a coding and modulation unit that generates a transmission signal by modulating an oscillator signal with an encoded bit signal. During a first and a second time segment, the encoded bit signal assumes a first and a second logic level, respectively. The transmission signal includes a first signal pulse having a first phase within the first time segment and a second signal pulse having a second phase that is shifted with respect to the first phase by a predefined phase difference within the second time segment. The transmission signal is paused for a pause period between the first and the second signal pulse. The pause period is shorter than a mean value of a period of the first time segment and a period of the second time segment.

First claim

The invention claimed is:

1. A radio frequency identification (RFID) transponder, comprising:
a coding and modulation circuit configured to generate a transmission signal during a transmission period by modulating an oscillator signal with an encoded bit signal, the encoded bit signal having, during a first time segment of the transmission period, a first logic level and having, during a second time segment of the transmission period, a second logic level different from the first logic level; and
wherein the transmission signal comprises:
within the first time segment, a first signal pulse having a frequency of the oscillator signal and a first phase depending on the first logic level; and
within the second time segment, a second signal pulse having the frequency and a second phase depending on the second logic level and shifted with respect to the first phase by a phase difference; and

wherein the coding and modulation circuit is further configured to pause the transmission signal for a pause period between the first signal pulse and the second signal pulse, wherein the pause period is shorter than or equal to a period of the first signal pulse and wherein the pause period is shorter than or equal to a period of the second signal pulse.

2. The RFID transponder according to claim 1 , wherein the coding and modulation circuit is further configured to generate the encoded bit signal based on a data bit signal, wherein the data bit signal represents data to be transmitted by the RFID transponder to a reading device.

3. The RFID transponder according to claim 2 , wherein the coding and modulation circuit is further configured, for generating the encoded bit signal, to apply a coding algorithm to the data bit signal.

4. The RFID transponder according to claim 2 , wherein the coding and modulation circuit is further configured to generate the encoded bit signal based on the data bit signal and on a subcarrier signal, wherein the subcarrier signal is a binary clock signal with a subcarrier frequency being smaller than the frequency of the oscillator signal.

5. The RFID transponder according to claim 4 , wherein the encoded bit signal corresponds to the subcarrier signal with a phase depending on a logic level of the data bit signal.

6. The RFID transponder according to claim 1 , wherein the encoded bit signal is generated to have a value that switches from the first logic level to the second logic level exactly once during the transmission period.

7. The RFID transponder according to claim 1 , further comprising:
an antenna;
a front end circuit connected to the antenna and configured to generate, during the pause period, a reader signal based on a radio-frequency field detected by the antenna; and
a phase-locked loop circuit configured to generate the oscillator signal and to synchronize the oscillator signal and the reader signal during a lock period within the pause period.

8. The RFID transponder according to claim 7 , wherein the phase-locked loop circuit is configured to synchronize the oscillator signal and the reader signal to have constant phase relationship therebetween during the lock period.

9. The RFID transponder according to claim 7 , wherein the phase-locked loop circuit is configured to operate in an unlocked mode at times outside of the lock period such that the oscillator signal and the reader signal are not synchronized during the unlocked mode.

10. The RFID transponder according to claim 7 , further comprising a damping circuit configured to attenuate the antenna at least during a part of the pause period.

11. The RFID transponder according to claim 10 , wherein the damping circuit is configured to attenuate the antenna during an attenuation period within the pause period, said attenuation period preceding the lock period.

12. The RFID transponder according to claim 1 , wherein the pause period begins before the first time segment has ended and wherein the pause period ends after the second time segment has begun.

13. A method for data transmission using radio frequency identification (RFID) technology, the method comprising:
generating a transmission signal during a transmission period by modulating an oscillator signal with an encoded bit signal, the oscillator signal having a frequency;
wherein the encoded bit signal has, during a first time segment of the transmission period, a first logic level and has, during a second time segment of the transmission period, a second logic level being different from the first logic level; and
wherein the transmission signal:
comprises, within the first time segment, a first signal pulse having the frequency of the oscillator signal and a first phase depending on the first logic level;
comprises, within the second time segment, a second signal pulse having the frequency of the oscillator signal and a second phase depending on the second logic level and being shifted with respect to the first phase by a phase difference; and
is paused for a pause period between the first signal pulse and the second signal pulse, wherein the pause period is shorter than or equal to a period of the first signal pulse and wherein the pause period is shorter than or equal to a period of the second signal pulse.

14. The method according to claim 13 , further comprising generating the encoded bit signal based on a data bit signal, wherein the data bit signal represents data to be transmitted.

15. The method according to claim 13 , further comprising:
detecting a radio-frequency field;
generating, during the pause period, a reader signal based the radio-frequency field; and
synchronizing the oscillator signal and the reader signal during a lock period within the pause period.

16. A radio frequency identification (RFID) transponder, comprising:
a coding and modulation circuit configured to generate a transmission signal during a transmission period by modulating an oscillator signal with an encoded bit signal, the encoded bit signal having, during a first time segment of the transmission period, a first logic level and having, during a second time segment of the transmission period, a second logic level different from the first logic level; and
wherein the transmission signal comprises:
within the first time segment, a first signal pulse having a frequency of the oscillator signal and a first phase depending on the first logic level; and
within the second time segment, a second signal pulse having the frequency and a second phase depending on the second logic level and shifted with respect to the first phase by a phase difference; and

wherein the coding and modulation circuit is further configured to pause the transmission signal for a pause period between the first signal pulse and the second signal pulse, wherein the pause period is shorter than or equal to a sum of a period of the first signal pulse and a period of the second signal pulse.

17. The RFID transponder according to claim 16 , wherein the coding and modulation circuit is further configured to generate the encoded bit signal based on a data bit signal, wherein the data bit signal represents data to be transmitted by the RFID transponder to a reading device.

18. The RFID transponder according to claim 17 , wherein the coding and modulation circuit is further configured, for generating the encoded bit signal, to apply a coding algorithm to the data bit signal.

19. The RFID transponder according to claim 17 , wherein the coding and modulation circuit is further configured to generate the encoded bit signal based on the data bit s

Assignees

• St Microelectronics Int Nv

Inventors

• Kovacic Kosta
• Pevec Albin
• Stiglic Maksimiljan

Classifications

• G06K19/07749

  the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card · CPC title

• G06K19/0723

  the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs · CPC title

• G06K19/0715

  the arrangement including means to regulate power transfer to the integrated circuit · CPC title

• G06K7/0008

  General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer · CPC title

• H04B5/0068 Primary

  Electricity · mapped topic