Abstract: A communications device is disclosed that includes a united integrated circuit card (UICC) that provides a single wire protocol (SWP) current signal to a near field communications (NFC) device. The SWP current signal is filtered by a filter to remove noise from the SWP current signal. The filter is precharged by a reference voltage when the SWP current signal is in a low state and then filters the SWP current signal when the SWP current signal is in a high state. A switching network provides the filter with the reference voltage to precharge when the SWP is current signal is in the low state and then provides the filter with the SWP current signal to filter when the SWP current signal is in the high state.

Abstract: A communications device is disclosed that includes a united integrated circuit card (UICC) that provides a single wire protocol (SWP) current signal to a near field communications (NFC) device. The SWP current signal is filtered by a filter to remove noise from the SWP current signal. The filter is precharged by a reference voltage when the SWP current signal is in a low state and then filters the SWP current signal when the SWP current signal is in a high state. A switching network provides the filter with the reference voltage to precharge when the SWP is current signal is in the low state and then provides the filter with the SWP current signal to filter when the SWP current signal is in the high state.

Abstract: An NFC communicator has a coupler operable to couple with a coupler of a near field RF communicator in near field range to enable communication of data between the communicators by modulation of a magnetic field, a demodulator to extract modulation from a modulated signal coupled to the coupler, and a modulator to modulate an RF signal in accordance with data to be communicated by the NFC communicator. The NFC communicator communicates with a data source and is arranged to at least one of provide timing data to the data source and receive timing data from the data source.

Abstract: A near field RF communicator has an inductive coupler to enable inductive coupling with a magnetic field of an RF signal; a rectifier to rectify an AC voltage derived from an RF signal inductively coupled to the inductive coupler; and a regulator to regulate a voltage derived from an RF signal inductively coupled to the inductive coupler, the regulator having a voltage-controlled impedance and a regulator controller to provide a control voltage for the voltage controlled impedance and to vary the control voltage in dependence upon a current flowing through the voltage controlled impedance. To prevent the voltage regulator from drawing excess current and energy from an RF field in which the communicator is present the voltage regulator is controlled to provide a chosen impedance characteristic.

Abstract: A near field RF communicator has an antenna circuit to couple with the H field of an RF magnetic field and a power supply deriver to derive a rectified auxiliary power supply from the received magnetic field. Rectification may be performed using an actively switched rectifier having a passive mode of operation. A sub regulation system is provided to regulate the auxiliary power supply to inhibit the possibility of temporally varying power requirements of the near field RF communicator or its host causing an apparent load modulation of a signal that is transmitted or received by the communicator.

Abstract: A communications device configured to couple with a near field RF communicator, in near field range, to enable communication of data by modulation of a magnetic field. The communications device also including a secure element, having a plurality of memory areas with differing levels of access, configured to provide secure data storage for transaction data, wherein the levels of access are differentiated by a degree to which the plurality of memory areas are programmable, writable and modifiable. Further, the communications device includes a controller configured to read the transaction data from the at least one secure element, and to cause a modulator to modulate the RF signal in accordance with transaction data read from the secure element so as to communicate the read transaction data to the near field RF communicator as proof of the transaction to enable an action related to the transaction to be carried out.

Abstract: A near field RF communicator has an inductive coupler (223) to enable inductive coupling with a magnetic field of an RF signal; a rectifier (213,214,215,216) to rectify an AC voltage derived from an RF signal inductively coupled to the inductive coupler (223); and a regulator (209,210,211,220,221,900) to regulate a voltage derived from an RF signal inductively coupled to the inductive coupler, the regulator having a voltage-controlled impedance (210, 211) and a regulator controller (209) to provide a control voltage for the voltage controlled impedance and to vary the control voltage in dependence upon a current flowing through the voltage controlled impedance (210, 211). To prevent the voltage regulator from drawing excess current and energy from an RF field in which the communicator is present the voltage regulator is controlled to provide a chosen impedance characteristic.

Abstract: A near field RF communicator has an antenna circuit (120) to receive a modulated radio frequency signal by inductive coupling and demodulation circuitry (130 or 131) to extract the modulation from a received modulated radio frequency signal inductively coupled to the antenna circuit. The demodulation circuitry has a virtual earth input comprising a current mirror. The demodulation circuitry may be formed by an amplifier (115 or 116) and a demodulator (114) coupled to an output of the amplifier. The amplifier may be a single input amplifier (116) coupled to an output of the antenna circuit or may be a differential amplifier (115) having first and second inputs to receive the modulated radio frequency signal from first and second outputs of the antenna circuit, with each amplifier input providing a virtual earth input.

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 circuit (102) to couple with the H field of an RF magnetic field and a power supply deriver (301) to derive a rectified auxiliary power supply from the received magnetic field. Rectification may be performed using an actively switched rectifier (502) having a passive mode of operation. A sub regulation system (506) is provided to regulate the auxiliary power supply to inhibit the possibility of temporally varying power requirements of the near field RF communicator or its host causing an apparent load modulation of a signal that is transmitted or received by the communicator.

Abstract: A communications device has a NFC communicator (15) having a coupler (17) to couple with a coupler of a near field RF communicator in near field range to enable communication of data between the communicators by modulation of a magnetic field, a demodulator (42) to extract modulation from a modulated signal coupled to the coupler and a modulator (40) to modulate an RF signal in accordance with data to be communicated by the NFC communicator. The device also has at least one secure element (30; 31) separate from the near field RF communicator (15) to provide secure data storage for transaction data representing or relating to a transaction.

Abstract: A NFC communicator or NFC communications enabled device has a data store to store data, a coupler to couple inductively with the magnetic field of a radio frequency signal and a signal generator to supply a radio frequency signal to the coupler. A modulator is provided to modulate a radio frequency signal in accordance with data and a demodulator is provided to extract data from a modulated radio frequency signal inductively coupled to the coupler. A controller enables the NFC communicator or NFC communications enabled device both to initiate near field radio frequency communication with another near field RF communicator and to respond to near field radio frequency communication initiated by another near field RF communicator. The NFC communicator or NFC communications enabled device also has a power deriver that derives power from a radio frequency signal inductively coupled to the coupler to charge a chargeable power supply.

Abstract: An NFC-enabled device configured at least in part as an integrated circuit, the integrated circuit including a controller and a plurality of capacitors. The controller is operable to control one or more of the plurality of capacitors to vary an operating parameter of the NFC-enabled device.

Abstract: A near field RF communicator has an inductive coupler to couple inductively to an H field of an RF signal from another near field RF communicator in near field range to provide a received signal, a demodulator coupled to extract any modulation from a source signal representing a received RF signal to provide an extracted modulation signal; and a controller coupled to receive an extracted modulation signal from the demodulator. The demodulator has a sampler to sample the source signal in sampling periods and to compare signal samples with at least one of other signal samples and a clock or reference signal to remove or reject the carrier of the received RF signal and to extract the modulation.

Abstract: An NFC communicator has an antenna circuit to enable inductive coupling, via an RF H field, of the NFC communicator and another near field RF communicator in near field range. The antenna circuit has an antenna element coupled in parallel with a first capacitor to form a parallel LC circuit. The antenna element has an antenna coil in series with a second capacitor to reduce the voltage to which circuitry of the NFC communicator is subjected by a received RF H field. Alternatively or additionally, receive circuitry of the NFC communicator may be coupled to only a proportion of the antenna coil to reduce the voltage to which circuitry of the NFC communicator is subjected by a received RF H field.