公开(公告)号：US20180040953A1

公开(公告)日：2018-02-08

申请号：US15227614

申请日：2016-08-03

Applicant: NXP B.V.

Inventor： Michael Gebhart ,  Fred George Nunziata ,  Hubert Watzinger

IPC: H01Q3/30 ,  H01Q1/22

CPC classification number: H01Q3/30 ,  H01Q1/2291 ,  H04B5/0031 ,  H04B5/0056

Abstract: A Near Field Communication (NFC) enabled device is disclosed. The NFC device includes an antenna. The NFC device also includes an impedance matching network, a carrier frequency generator to generate a carrier wave, a receiver for receiving a magnetic induction wave, a transmitter, a driver circuit configured to alter an impedance of an antenna network associated with the antenna between a first impedance and a second impedance and a control unit. The control unit is configured to derive a first phase difference between the received magnetic induction wave and an internal clock at the first impedance and a second phase difference between the received magnetic induction wave and the internal clock at the second impedance. The control unit is further configured to change a phase of the carrier wave based on a difference between the first phase difference and a second phase difference.

公开(公告)号：US11005534B2

公开(公告)日：2021-05-11

申请号：US16988852

申请日：2020-08-10

Applicant: NXP B.V.

Inventor： Fred George Nunziata ,  Martin Buchsbaum ,  Erich Merlin ,  Adrian Rafael Krenn

IPC: H04B5/00

Abstract: In accordance with a first aspect of the present disclosure, a near field communication (NFC) device is provided, comprising: a modulator configured to modulate a carrier signal received from an external reader, resulting in a modulated carrier signal; a controller configured to control a transmission of the modulated carrier signal to the external reader; a transmitter driver configured to transmit said modulated carrier signal, said transmitter driver having a variable resistance; wherein the controller is further configured to change said variable resistance during a modulation phase of the NFC device such that a clock synchronization window is widened. In accordance with a second aspect of the present disclosure, a corresponding method of operating an NFC device is conceived. In accordance with a third aspect of the present disclosure, a non-transitory machine-readable medium is provided, comprising instructions which, when executed, carry out a method of the kind set forth.

公开(公告)号：US20170104468A1

公开(公告)日：2017-04-13

申请号：US14881095

申请日：2015-10-12

Applicant: NXP B.V.

Inventor： Leonhard Kormann ,  Markus Wobak ,  Fred George Nunziata

IPC: H03H7/38 ,  H04B5/00

CPC classification number: H03H7/38 ,  G06K7/10148 ,  G06K7/10158 ,  G06K7/10217 ,  H04B5/0056

Abstract: A near field communication (NFC) or Radio Frequency Identification (RFID) reader device for contact-less communication includes a transmitter block connected to an antenna via a matching circuitry. An electromagnetic carrier signal and modulated data information are emitted via this main antenna. Any secondary object brought into the vicinity of the main antenna influences the primary resonant circuit resulting in a load change seen by the transmitter. This detuning can cause increased power consumption, RF (Radio Frequency) standard incompliance, and device damage. The present disclosure describes devices and methods on how to detect detuning and how to regulate the transmitter's output.

公开(公告)号：US10164600B2

公开(公告)日：2018-12-25

申请号：US14881095

申请日：2015-10-12

Applicant: NXP B.V.

Inventor： Leonhard Kormann ,  Markus Wobak ,  Fred George Nunziata

IPC: G06K7/10 ,  H03H7/38 ,  H04B5/00

Abstract: A near field communication (NFC) or Radio Frequency Identification (RFID) reader device for contact-less communication includes a transmitter block connected to an antenna via a matching circuitry. An electromagnetic carrier signal and modulated data information are emitted via this main antenna. Any secondary object brought into the vicinity of the main antenna influences the primary resonant circuit resulting in a load change seen by the transmitter. This detuning can cause increased power consumption, RF (Radio Frequency) standard incompliance, and device damage. The present disclosure describes devices and methods on how to detect detuning and how to regulate the transmitter's output.

公开(公告)号：US09997829B2

公开(公告)日：2018-06-12

申请号：US15227614

申请日：2016-08-03

Applicant: NXP B.V.

Inventor： Michael Gebhart ,  Fred George Nunziata ,  Hubert Watzinger

IPC: H01Q3/30 ,  H01Q1/22

CPC classification number: H01Q3/30 ,  H01Q1/2291 ,  H04B5/0031 ,  H04B5/0056

Abstract: A Near Field Communication (NFC) enabled device is disclosed. The NFC device includes an antenna. The NFC device also includes an impedance matching network, a carrier frequency generator to generate a carrier wave, a receiver for receiving a magnetic induction wave, a transmitter, a driver circuit configured to alter an impedance of an antenna network associated with the antenna between a first impedance and a second impedance and a control unit. The control unit is configured to derive a first phase difference between the received magnetic induction wave and an internal clock at the first impedance and a second phase difference between the received magnetic induction wave and the internal clock at the second impedance. The control unit is further configured to change a phase of the carrier wave based on a difference between the first phase difference and a second phase difference.

公开(公告)号：US09654181B1

公开(公告)日：2017-05-16

申请号：US14968788

申请日：2015-12-14

Applicant: NXP B.V.

Inventor： Markus Wobak ,  Leonhard Kormann ,  Fred George Nunziata

IPC: H04B5/00

CPC classification number: H04B5/0031 ,  H04B5/0037 ,  H04B5/0075 ,  H04B17/101

Abstract: Transmitter (TX) modulation envelope parameters are defined in RF standards (e.g., ISO 14443, NFC Forum, EMVCo). These envelope parameters include rise/fall times, modulation index, etc. For standards compliancy, these envelope parameters must be within the respective limits. For example, shaping parameters are influenced by detuning the antenna with a counterpart device like a card or mobile phone, or by thermal influences on the matching network. This disclosure describes an NFC or RFID device that is able to detect and measure the detuning on the antenna and/or the matching network change. With this information, the NFC or RFID device can dynamically control the shaping parameters of the envelope, instead of relying on one single static configuration setting for the transmitter. In particular, changes in the Q (quality) factor are used for dynamically controlling the transmitter signal envelope shape for compensating the effect of antenna detuning and/or matching network variation.