Abstract: In some embodiments, a contactless communication device includes an antenna, and a driving stage having a power supply terminal configured to receive a power supply voltage, where the driving stage is configured to deliver a current to the antenna. The device further includes a monitoring circuit configured to monitor the power transmitted by the antenna. The monitoring circuit is configured, in the presence of a request for a reduction in a current level of transmitted power, to reduce the power supply voltage of the driving stage down to a target value corresponding to a new level of the transmitted power less than the current level.

Abstract: A method for a phase calibration in a frontend circuit of a near field communication (NFC) tag device is disclosed. An active load modulation signal is generated with a preconfigured value of a phase difference with respect to a reference signal of an NFC signal generator device. An amplitude of a test signal present at an antenna of the NFC tag device is measured. The test signal results from overlaying of the reference signal with the active load modulation signal. The following steps are repeated: modifying the value of the phase difference, providing the active load modulation signal with the modified value of the phase difference, measuring an amplitude of the test signal and comparing the measured amplitude with the previously measured amplitude until the measured amplitude fulfills a predefined condition. The value of the phase difference corresponding to the previously measured amplitude is stored.

Abstract: In a general aspect, a method can include producing, by an inductive antenna circuit, a first periodic signal that is based on an alternating external magnetic field; producing, by an oscillator circuit, a second periodic signal that is based on the first periodic signal; and transmitting, in correspondence with a data-carrying modulation signal, a sequence of data bits. The transmitting can include sequentially and repetitively: applying, with the oscillator circuit operating in a free oscillation mode, the second periodic signal to the inductive antenna circuit; and inhibiting, with the oscillator circuit operating in a synchronous oscillation mode, application of the second periodic signal to the inductive antenna circuit. The synchronous oscillation mode of the oscillator circuit can cause the second periodic signal to be synchronized to the first periodic signal.

Abstract: A method for a phase calibration in a frontend circuit of a near field communication (NFC) tag device is disclosed. An active load modulation signal is generated with a preconfigured value of a phase difference with respect to a reference signal of an NFC signal generator device. An amplitude of a test signal present at an antenna of the NFC tag device is measured. The test signal results from overlaying of the reference signal with the active load modulation signal. The following steps are repeated: modifying the value of the phase difference, providing the active load modulation signal with the modified value of the phase difference, measuring an amplitude of the test signal and comparing the measured amplitude with the previously measured amplitude until the measured amplitude fulfills a predefined condition. The value of the phase difference corresponding to the previously measured amplitude is stored.

Abstract: According to an embodiment, a method can be performed by a first active near-field communication (NFC) device. The method includes assuming a field detection mode, generating an advertisement pulse, and checking whether a predefined condition is fulfilled. If the checking determines that the predefined condition is fulfilled, the method includes assuming an active mode and communicating with an adjacent active NFC device, and, if the checking does not determine that the predefined condition is fulfilled, the method includes staying in the field detection mode and generating another advertisement pulse.

Abstract: In a general aspect, a method can include producing, by an inductive antenna circuit, a first periodic signal that is based on an alternating external magnetic field; producing, by an oscillator circuit, a second periodic signal that is based on the first periodic signal; and transmitting, in correspondence with a data-carrying modulation signal, a sequence of data bits. The transmitting can include sequentially and repetitively: applying, with the oscillator circuit operating in a free oscillation mode, the second periodic signal to the inductive antenna circuit; and inhibiting, with the oscillator circuit operating in a synchronous oscillation mode, application of the second periodic signal to the inductive antenna circuit. The synchronous oscillation mode of the oscillator circuit can cause the second periodic signal to be synchronized to the first periodic signal.

Abstract: In a general aspect, a mobile communications apparatus can include a housing and inductive coupling communication circuitry configured to communicate in peer-to-peer mode with a like apparatus. The inductive coupling communication circuitry can include a communication controller and an inductive antenna. The inductive antenna can have at least one loop arranged in series between a first connection point and a second connection point and be proximate to a back wall of the housing. The inductive antenna can be, when the mobile communications apparatus is placed back-to-back in longitudinal and latitudinal alignment with a like mobile communications device, asymmetric with a like inductive antenna of the like mobile communications device, where a ratio of a sum of respective surface areas of mutually opposite surfaces of loops of a same rank of the inductive antenna divided by a sum of respective surface areas of the like inductive antenna is 0.8 or less.

Abstract: According to an embodiment, a method can be performed by a first active near-field communication (NFC) device. The method includes assuming a field detection mode, generating an advertisement pulse, and checking whether a predefined condition is fulfilled. If the checking determines that the predefined condition is fulfilled, the method includes assuming an active mode and communicating with an adjacent active NFC device, and, if the checking does not determine that the predefined condition is fulfilled, the method includes staying in the field detection mode and generating another advertisement pulse.

Abstract: In a general aspect, a method can include producing, by an inductive antenna circuit, a first periodic signal that is based on an alternating external magnetic field; producing, by an oscillator circuit, a second periodic signal that is based on the first periodic signal; and transmitting, in correspondence with a data-carrying modulation signal, a sequence of data bits. The transmitting can include sequentially and repetitively: applying, with the oscillator circuit operating in a free oscillation mode, the second periodic signal to the inductive antenna circuit; and inhibiting, with the oscillator circuit operating in a synchronous oscillation mode, application of the second periodic signal to the inductive antenna circuit. The synchronous oscillation mode of the oscillator circuit can cause the second periodic signal to be synchronized to the first periodic signal.

Abstract: A method for a phase calibration in a frontend circuit of a near field communication (NFC) tag device is disclosed. An active load modulation signal is generated with a preconfigured value of a phase difference with respect to a reference signal of an NFC signal generator device. An amplitude of a test signal present at an antenna of the NFC tag device is measured. The test signal results from overlaying of the reference signal with the active load modulation signal. The following steps are repeated: modifying the value of the phase difference, providing the active load modulation signal with the modified value of the phase difference, measuring an amplitude of the test signal and comparing the measured amplitude with the previously measured amplitude until the measured amplitude fulfills a predefined condition.

Abstract: In a general aspect, a mobile communications apparatus can include a housing and inductive coupling communication circuitry configured to communicate in peer-to-peer mode with a like apparatus. The inductive coupling communication circuitry can include a communication controller and an inductive antenna. The inductive antenna can have at least one loop arranged in series between a first connection point and a second connection point and be proximate to a back wall of the housing. The inductive antenna can be, when the mobile communications apparatus is placed back-to-back in longitudinal and latitudinal alignment with a like mobile communications device, asymmetric with a like inductive antenna of the like mobile communications device, where a ratio of a sum of respective surface areas of mutually opposite surfaces of loops of a same rank of the inductive antenna divided by a sum of respective surface areas of the like inductive antenna is 0.8 or less.

Abstract: A method for sending data by inductive coupling includes: extracting an antenna signal from an antenna circuit, extracting from the antenna signal a first periodic signal, producing a second periodic signal by way of a synchronous oscillator, placing the oscillator in a free oscillation mode and applying to the antenna circuit the second periodic signal, modifying the impedance of the antenna circuit, restoring the amplitude of the antenna signal, then resynchronizing the oscillator on the first periodic signal.

Abstract: An apparatus including inductive coupling communication circuitry configured to communicate in peer-to-peer mode with an identical apparatus includes an antenna coil presenting, relative to a longitudinal median or a transversal median axis of the antenna coil, an asymmetry corresponding to a coverage rate less than or equal to 0.6 if the antenna coil comprises 4 or more loops, less than or equal to 0.7 if the antenna coil comprises 3 loops, or less than or equal to 0.8 if the antenna coil comprises 1 or 2 loops.

Abstract: A method for sending data by inductive coupling includes: extracting an antenna signal from an antenna circuit, extracting from the antenna signal a first periodic signal, producing a second periodic signal by way of a synchronous oscillator, placing the oscillator in a free oscillation mode and applying to the antenna circuit the second periodic signal, modifying the impedance of the antenna circuit, restoring the amplitude of the antenna signal, then resynchronizing the oscillator on the first periodic signal.

Abstract: A contactless integrated circuit includes modulation and demodulation circuits configured to connect to an HF antenna circuit to emit and receive HF signals by inductive coupling in a reader mode, modulation and demodulation circuits configured to connect to a UHF antenna to emit and receive UHF signals by electric coupling in a reader mode, a data processing circuit connected to the modulation and demodulation circuits, and configured to provide data to be emitted to the modulation circuits, and to process received signals, transmitted by the demodulation circuits, the demodulation circuits including a common demodulation circuit to equally process signals received by the UHF and HF antennas.

Abstract: An NFC card includes an antenna circuit including an antenna coil having at least one magnetic axis, and at least one integrated circuit linked to the antenna circuit. The magnetic axis of the antenna coil is substantially parallel to at least one side of the card, and the card further includes at least one electrically conductive screen extending near the antenna coil, which does not cross the magnetic axis. The card does not include any magnetically permeable material between the at least one conductive screen and the antenna coil. Embodiments of the invention are applicable in particular to SIM-NFC card and SD-NFC cards.

Abstract: An NFC card includes an antenna circuit including an antenna coil having at least one magnetic axis, and at least one integrated circuit linked to the antenna circuit. The magnetic axis of the antenna coil is substantially parallel to the plane of the card, and is at an angle of 45°±25° with respect to a longitudinal axis LX of the card. Embodiments of the invention are applicable in particular to SIM-NFC card and SD-NFC cards.

Abstract: A device includes a radio transceiver equipped with a UHF antenna, a clock generator associated with the radio transceiver, a processor configured to periodically connect to the radiotelephony network by way of the radio transceiver, and a UHF tag reader configured to conduct a transaction with a UHF tag only outside periods of connection of the processor to the radiotelephony network. The device is particularly directed for use in mobile telephones.

Abstract: A method for sending data by inductive coupling includes: extracting an antenna signal from an antenna circuit, extracting from the antenna signal a first periodic signal, producing a second periodic signal by way of a synchronous oscillator, placing the oscillator in a free oscillation mode and applying to the antenna circuit the second periodic signal, modifying the impedance of the antenna circuit, restoring the amplitude of the antenna signal, then resynchronizing the oscillator on the first periodic signal.

Abstract: A contactless integrated circuit includes modulation and demodulation circuits configured to connect to an HF antenna circuit to emit and receive HF signals by inductive coupling in a reader mode, modulation and demodulation circuits configured to connect to a UHF antenna to emit and receive UHF signals by electric coupling in a reader mode, a data processing circuit connected to the modulation and demodulation circuits, and configured to provide data to be emitted to the modulation circuits, and to process received signals, transmitted by the demodulation circuits, the demodulation circuits including a common demodulation circuit to equally process signals received by the UHF and HF antennas.