Abstract: A near field communications (NFC) device is disclosed that load modulates and regulates a radio frequency (RF) signal. The NFC device includes a rectifier that rectifies the RF signal to provide a direct current voltage. The NFC device also includes a modulator that modulates a data signal. The modulator provides a first voltage when the data signal is at a first level and provides a second voltage when the data signal is at a second level. The NFC device utilizes a regulator to regulate and to load modulate the RF signal. The regulator adjusts an impedance based upon a comparison of the DC voltage provided by the regulator to the first voltage provided by the modulator for the data signal at the first level or to the second voltage provided by the modulator for the data signal at the second level.

Abstract: Embodiments of the present disclosure can be used to produce smaller, more compact antenna drivers at a reduced cost. Systems and methods for integrating components of an antenna driver with components of a shunt regulator and clamp are provided. By combining these components according to embodiments of the present disclosure, transistor count in an antenna driver can be reduced. This integrated device advantageously allows antenna driver functionality, regulator functionality, and clamp control functionality to be provided at a reduced manufacturing cost and with reduced real estate.

Abstract: A communication device is disclosed that includes an antenna circuit with coupling connections that are used interchangeably as a receive coupling connection and a transmit coupling connection for an RF signal. A driver maintains a constant voltage or a constant current on a first coupling connection of the antenna circuit based on a drive signal that includes an output voltage and an output current. A demodulator extracts modulation from the RF signal based on a fluctuating voltage or a fluctuating current on a second coupling connection of the antenna circuit.

Abstract: A wireless communication device for communicating in the near-field via active load modulation. The device including an antenna configured to receive a magnetic field, a recovery device configured to recover a clock from the magnetic field, and a multiplexer configured to receive the recovered clock and a reference clock, and to output one of the recovered clock and the reference clock based on a current operational state of the wireless communication device, The wireless communication device further including a shunt regulator configured to produce the active load modulation by modulating an impedance of the wireless communication device, a phase-locked loop (PLL) configured to receive one of the recovered clock and the reference clock and to utilize the received clock to control the active load modulation, and a driver configured to contribute to the active load modulation by adjusting an amplitude of a voltage across the antenna.

Abstract: Embodiments of the present disclosure can be used to produce smaller, more compact antenna drivers at a reduced cost. Systems and methods for integrating components of an antenna driver with components of a shunt regulator and clamp are provided. By combining these components according to embodiments of the present disclosure, transistor count in an antenna driver can be reduced. This integrated device advantageously allows antenna driver functionality, regulator functionality, and clamp control functionality to be provided at a reduced manufacturing cost and with reduced real estate.

Abstract: A near field communications (NFC) device is disclosed that load modulates and regulates a radio frequency (RF) signal. The NFC device includes a rectifier that rectifies the RF signal to provide a direct current voltage. The NFC device also includes a modulator that modulates a data signal. The modulator provides a first voltage when the data signal is at a first level and provides a second voltage when the data signal is at a second level. The NFC device utilizes a regulator to regulate and to load modulate the RF signal. The regulator adjusts an impedance based upon a comparison of the DC voltage provided by the regulator to the first voltage provided by the modulator for the data signal at the first level or to the second voltage provided by the modulator for the data signal at the second level.

Abstract: A communication device is disclosed that includes an antenna circuit with coupling connections that are used interchangeably as a receive coupling connection and a transmit coupling connection for an RF signal. A driver maintains a constant voltage or a constant current on a first coupling connection of the antenna circuit based on a drive signal that includes an output voltage and an output current. A demodulator extracts modulation from the RF signal based on a fluctuating voltage or a fluctuating current on a second coupling connection of the antenna circuit.

Abstract: A near field communications (NFC) device is disclosed that load modulates and regulates a radio frequency (RF) signal. The NFC device includes a rectifier that rectifies the RF signal to provide a direct current voltage. The NFC device also includes a modulator that modulates a data signal. The modulator provides a first voltage when the data signal is at a first level and provides a second voltage when the data signal is at a second level. The NFC device utilizes a regulator to regulate and to load modulate the RF signal. The regulator adjusts an impedance based upon a comparison of the DC voltage provided by the regulator to the first voltage provided by the modulator for the data signal at the first level or to the second voltage provided by the modulator for the data signal at the second level.

Abstract: Embodiments of the present disclosure can be used to produce smaller, more compact antenna drivers at a reduced cost. Systems and methods for integrating components of an antenna driver with components of a shunt regulator and clamp are provided. By combining these components according to embodiments of the present disclosure, transistor count in an antenna driver can be reduced. This integrated device advantageously allows antenna driver functionality, regulator functionality, and clamp control functionality to be provided at a reduced manufacturing cost and with reduced real estate.

Abstract: A wireless communication device for communicating in the near-field via active load modulation. The device including an antenna configured to receive a magnetic field, a recovery device configured to recover a clock from the magnetic field, and a multiplexer configured to receive the recovered clock and a reference clock, and to output one of the recovered clock and the reference clock based on a current operational state of the wireless communication device, The wireless communication device further including a shunt regulator configured to produce the active load modulation by modulating an impedance of the wireless communication device, a phase-locked loop (PLL) configured to receive one of the recovered clock and the reference clock and to utilize the received clock to control the active load modulation, and a driver configured to contribute to the active load modulation by adjusting an amplitude of a voltage across the antenna.

Abstract: A communications device is disclosed that includes an antenna circuit with coupling connections that are used interchangeably as a receive coupling connection and a transmit coupling connection for an RF signal. A driver maintains a constant voltage or a constant current on a first coupling connection of the antenna circuit based on a drive signal that includes an output voltage and an output current. A demodulator extracts modulation from the RF signal based on a fluctuating voltage or a fluctuating current on a second coupling connection of the antenna circuit.

Abstract: A wireless communication device for communicating in the near-field via active load modulation. The device including an antenna configured to receive a magnetic field, a recovery device configured to recover a clock from the magnetic field, and a multiplexer configured to receive the recovered clock and a reference clock, and to output one of the recovered clock and the reference clock based on a current operational state of the wireless communication device, The wireless communication device further including a shunt regulator configured to produce the active load modulation by modulating an impedance of the wireless communication device, a phase-locked loop (PLL) configured to receive one of the recovered clock and the reference clock and to utilize the received clock to control the active load modulation, and a driver configured to contribute to the active load modulation by adjusting an amplitude of a voltage across the antenna.

Abstract: A wireless communication device for communicating in the near-field via active load modulation. The device including an antenna configured to receive a magnetic field, a recovery device configured to recover a clock from the magnetic field, and a multiplexer configured to receive the recovered clock and a reference clock, and to output one of the recovered clock and the reference clock based on a current operational state of the wireless communication device, The wireless communication device further including a shunt regulator configured to produce the active load modulation by modulating an impedance of the wireless communication device, a phase-locked loop (PLL) configured to receive one of the recovered clock and the reference clock and to utilize the received clock to control the active load modulation, and a driver configured to contribute to the active load modulation by adjusting an amplitude of a voltage across the antenna.

Abstract: An apparatus and method is disclosed to provide improved NFC communications. A first NFC device antenna transmits information to a second NFC device by driving an antenna module with a current to generate a magnetic field. The magnetic field is modulated and the information is transmitted according to a first set of operating parameters. A second NFC device harvests power from the magnetic field and communicates information to the first NFC device by modulating the magnetic field according to a second set of operating parameters, which is received by the first NFC device. The first NFC device recovers a signal metric from the modulated magnetic field. The first NFC device uses the signal metric to provide feedback regarding the second set of operating parameters. Various systems are presented to utilize the signal metric feedback and provide efficient and reliable communications between the first and second NFC devices.

Abstract: Embodiments of the present disclosure can be used to produce smaller, more compact antenna drivers at a reduced cost. Systems and methods for integrating components of an antenna driver with components of a shunt regulator and clamp are provided. By combining these components according to embodiments of the present disclosure, transistor count in an antenna driver can be reduced. This integrated device advantageously allows antenna driver functionality, regulator functionality, and clamp control functionality to be provided at a reduced manufacturing cost and with reduced real estate.

Abstract: An in-phase, quadrature phase (IQ) mixer for a near field communications (NFC) device is disclosed that includes a signal provider that provides an in-phase (I) mixing signal and a quadrature phase (Q) mixing signal so that the period of the I mixing signal is equal to a period for the Q mixing signal. A controller is configured to control the signal provider so that the average of the I mixing signal over two periods is minimized and the average of the Q mixing signal over two periods is also minimized. The controller is also configured to control the signal provider so that the average propagation delay for the I mixing signal and the Q mixing signal is minimized individually and relative to each other.

Abstract: An in-phase, quadrature phase (IQ) mixer for a near field communications (NFC) device is disclosed that includes a signal provider that provides an in-phase (I) mixing signal and a quadrature phase (Q) mixing signal so that the period of the I mixing signal is equal to a period for the Q mixing signal. A controller is configured to control the signal provider so that the average of the I mixing signal over two periods is minimized and the average of the Q mixing signal over two periods is also minimized. The controller is also configured to control the signal provider so that the average propagation delay for the I mixing signal and the Q mixing signal is minimized individually and relative to each other.

Abstract: A near field RF communicator has: an antenna operable to generate an RF signal to enable inductive coupling via the magnetic field of the RF signal between the antenna and another near field RF communicator or RF transponder in near field range; and a signal generator operable to generate a multi-level digital sine wave drive signal to drive the antenna to generate the RF signal, wherein the signal generator comprises a selector operable to select one or more digital sequences to provide one or more digital signals from which the digital sine wave drive signal is generated.

Abstract: A driver (107, 401, R6; 107, 402, R8, R7; 107, 500, 501) provides a drive signal having an output voltage and an output current to drive an inductive coupler (102) of a near field RF communicator such as an NFC communicator. A demodulator (114) extracts modulation from an RF signal coupled to the inductive coupler. The driver is arranged to maintain one of the output current and the output voltage substantially constant to enable the demodulator to extract modulation from an RF signal on the basis of variation in the other of the output current and the output voltage.

Abstract: A near field communications (NFC) device is disclosed that load modulates and regulates a radio frequency (RF) signal. The NFC device includes a rectifier that rectifies the RF signal to provide a direct current voltage. The NFC device also includes a modulator that modulates a data signal. The modulator provides a first voltage when the data signal is at a first level and provides a second voltage when the data signal is at a second level. The NFC device utilizes a regulator to regulate and to load modulate the RF signal. The regulator adjusts an impedance based upon a comparison of the DC voltage provided by the regulator to the first voltage provided by the modulator for the data signal at the first level or to the second voltage provided by the modulator for the data signal at the second level.