Method and device for phase calibration with active load modulation

Patent metadata

Field	Value
Publication number	US-10019608-B2
Application number	US-201514964488-A
Country	US
Kind code	B2
Filing date	Dec 9, 2015
Priority date	Dec 9, 2015
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A method for operating an RFID device is disclosed. In the embodiment, the method involves establishing a radio-frequency link, receiving signal samples of the radio-frequency link, determining the offset of an initial phase of the link by filtering noise from the signal samples, windowing the filtered signal samples, and calculating an offset value from phase differences between the windows of signal samples, and modifying a configuration profile based on the offset value. During data transmission the configuration profile can be used to configure the transmitter in order to maintain the constant phase during transmission.

First claim

What is claimed is:

1. A method for operating a radio-frequency identification (RFID) device, the method comprising:
establishing a radio-frequency link;
receiving signal samples of the radio-frequency link;
determining an offset of an initial phase of the radio-frequency link by:
filtering noise from the signal samples;
windowing the filtered signal samples; and
calculating an offset value from phase differences between a plurality of windows of the signal samples; and

modifying a configuration profile based on the offset value.

2. The method of claim 1 , wherein the method further comprises configuring an analog transponder to convert a message to an analog signal according to the configuration profile by trimming a clock offset.

3. The method of claim 1 , wherein signal samples are received by generating clock signals from the radio-frequency link.

4. The method of claim 1 , wherein the steps of receiving the signal samples, determining the offset, and modifying the configuration profile are repeated before each transmission by the RFID device.

5. The method of claim 1 , wherein the RFID device is calibrated without resonance tuning.

6. The method of claim 1 , wherein the RFID device is configured with a fixed resonance.

7. A method for operating an RFID device, the method comprising:
establishing a radio-frequency link with an RFID device;
receiving a configuration profile at the RFID device; and
trimming a clock offset of the RFID device with a dynamic transmission configuration circuit based on the configuration profile.

8. The method of claim 7 , wherein the method further comprises:
receiving signal samples of the radio-frequency link;
transmitting the signal samples to an external calibration device;
generating the configuration profile with the external calibration device by:
filtering noise from the signal samples;
windowing the signal samples; and
calculating an offset value from the phase difference between the signal samples; and

transmitting the configuration profile to the RFID device.

9. The method of claim 7 , wherein the method further comprises configuring an analog transponder to convert a message to an analog signal according to the configuration profile by trimming a clock offset.

10. The method of claim 7 , wherein the configuration profile is generated based on signal samples received by another RFID device having similar components.

11. The method of claim 7 , wherein the configuration profile is generated without resonance turning.

12. The method of claim 8 , wherein the steps of receiving the signal samples, transmitting the signal samples, generating the configuration profile, and transmitting the configuration profile are repeated before each transmission by the RFID device.

Assignees

• Nxp Bv

Inventors

• Neffe Ulrich
• Watzinger Hubert
• Stark Michael
• Bruckbauer Johannes
• Noisternig Thomas

Classifications

• H04B17/21

  for calibration; for correcting measurements · CPC title

• G06K7/10336

  the antenna being of the near field type, inductive coil · 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

• G06K7/10198 Primary

  setting parameters for the interrogator, e.g. programming parameters and operating modes · CPC title

• G06K7/0095 Primary

  Testing the sensing arrangement, e.g. testing if a magnetic card reader, bar code reader, RFID interrogator or smart card reader functions properly (testing of electrical circuits G01R31/28) · CPC title