Method and device for phase calibration with active load modulation

• US 10,019,608 B2
• Filed: 12/09/2015
• Issued: 07/10/2018
• Est. Priority Date: 12/09/2015
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Neffe, Ulrich, Watzinger, Hubert, Stark, Michael, Bruckbauer, Johannes, Noisternig, Thomas
• Primary Examiner(s): Neyzari, Ali
• Application Number:
  US14/964,488
• Publication Number:
  US 20170169258A1
• Time in Patent Office: 944 Days
• Field of Search: 340 101
• CPC Class Codes: G06K 17/0029 the arrangement being specially adapted for wireless interrogation of grouped or bundled articles tagged with wireless record carriers
• CPC Class Codes: G06K 19/0702 the arrangement including a battery
• CPC Class Codes: G06K 19/0712 the arrangement being capable of triggering distinct operating modes or functions dependent on the strength of an energy or interrogation field in the proximity of the record carrier active means for hindering electromagnetic reading or writing G06K19/07336
• CPC Class Codes: G06K 19/0723 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 Class Codes: G06K 7/0095 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 Class Codes: G06K 7/10198 setting parameters for the interrogator, e.g. programming parameters and operating modes
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/45 Transponders
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04L 2027/0036 using a recovered symbol clock
• CPC Class Codes: H04L 2027/0067 Phase error detectors
• CPC Class Codes: H04L 27/0014 Carrier regulation of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657

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.

Claims

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.