Abstract: A system for sensing a proximity of a near field communication (NFC) device includes an NFC reader that communicates with a remote NFC device through load modulation. The NFC reader transmits a wireless carrier signal from an antenna, and the remote NFC device modulates the carrier signal by changing its internal impedance in order to transmit data to the NFC reader. The NFC reader has at least one antenna for receiving the modulated signal. The antenna is coupled to circuitry that analyzes the signal received from the remote NFC device The circuitry then identifies a resonant frequency for the remote NFC device based on the received signal and controls transmission characteristics of the NFC reader for communicating with the remote NFC device based on the identified resonant frequency.

Abstract: A wearable device, such as a finger ring worn by a user, communicates information about a user to a reader that uses the information in order to perform a transaction. Such wearable device may be conveniently carried by and accessible to the user such that utilization of the device for the transaction is less burdensome for the user, thereby encouraging use of the device for particular transactions. Indeed, in some cases, such as when the device is implemented as a finger ring or other type of jewelry, the user may be encouraged to carry the device in an exposed manner such that it is readily available for the transaction without the user having to search in a wallet, pocket, or purse for the device.

Abstract: A system for performing payment transactions includes a wearable payment device, such as a finger ring worn by a user, that communicates payment data to a payment reader that uses the payment data in order to request a payment transaction. The system also includes a mobile communication device that receives an input associated with the payment transaction from the user and wirelessly transmits information to the wearable payment device based on the input. The wearable payment device can use the information from the mobile communication device for performing the payment transaction and transmit at least a portion of the information from the mobile communication device to the payment reader during the payment transaction.

Abstract: A near field communication (NFC) system includes an NFC reader that communicates with a remote NFC device through load modulation. The NFC reader transmits a wireless carrier signal from an antenna and has a plurality of passive receive antennas to receive the modulated signal. The NFC reader also has circuitry to provide a plurality of data streams that define data recovered from the modulated wireless carrier signal received from the plurality of receivers. The circuitry then selects, based on a location of the NFC device relative to the NFC reader, one of the plurality of data streams for use in processing a transaction.

Abstract: A wearable payment device, such as a finger ring worn by a user, communicates payment data via an antenna to a payment reader that uses the payment data in order to request a payment transaction. The wearable payment device can tune the antenna to enhance performance of the antenna. The wearable payment device can measure a characteristic of the antenna and perform an assessment of the performance of the antenna based on the measured characteristic. The antenna can be tuned, such as by changing the impedance of the antenna, based on the assessed performance of the antenna.

Abstract: A wireless communication device communicates with an inductively coupled device via a wireless carrier signal that may be modulated by both the wireless communication device and the inductively coupled device. The inductively coupled signal is transmitted from a transponder antenna of the wireless communication device. The wireless communication device also includes an auxiliary antenna. The auxiliary antenna is enabled while the wireless communication device is receiving a modulated version of the wireless carrier signal from the inductively coupled device.

Abstract: A wearable payment device, such as a finger ring worn by a user, communicates payment data to a payment reader that uses the payment data in order to request a payment transaction. Such wearable payment device may be conveniently carried by and accessible to the user such that utilization of the payment device for the payment transaction is less burdensome for the user, thereby encouraging use of the payment device for payments. Indeed, in some cases, such as when the payment device is implemented as a finger ring or other type of jewelry, the user may be encouraged to carry the payment device in an exposed manner such that it is readily available for the payment transaction without the user having to search in a wallet, pocket, or purse.

Abstract: A wearable payment device, such as a finger ring worn by a user, communicates payment data to a payment reader that uses the payment data in order to request a payment transaction. Such wearable payment device may be conveniently carried by and accessible to the user such that utilization of the payment device for the payment transaction is less burdensome for the user, thereby encouraging use of the payment device for payments. Indeed, in some cases, such as when the payment device is implemented as a finger ring or other type of jewelry, the user may be encouraged to carry the payment device in an exposed manner such that it is readily available for the payment transaction without the user having to search in a wallet, pocket, or purse.

Abstract: A system for sensing a proximity of a near field communication (NFC) device includes an NFC reader that communicates with a remote NFC device through load modulation. The NFC reader transmits a wireless carrier signal from an antenna, and the remote NFC device modulates such carrier signal by changing its internal impedance in order to transmit data to the NFC reader. The NFC reader has at least one antenna for receiving the modulated signal. This antenna is coupled to circuitry that measures a spectrum of the received signal and identifies a resonant frequency of the NFC device based on the measured spectrum. Such circuitry also determines the signal's amplitude at such resonant frequency and precisely estimates the distance of the remote NFC device from the reader based on such amplitude.

Abstract: A wearable payment device, such as a finger ring worn by a user, communicates payment data to a payment reader that uses the payment data in order to request a payment transaction. Such wearable payment device may be conveniently carried by and accessible to the user such that utilization of the payment device for the payment transaction is less burdensome for the user, thereby encouraging use of the payment device for payments. Indeed, in some cases, such as when the payment device is implemented as a finger ring or other type of jewelry, the user may be encouraged to carry the payment device in an exposed manner such that it is readily available for the payment transaction without the user having to search in a wallet, pocket, or purse.

Abstract: A wearable payment device, such as a finger ring worn by a user, communicates payment data to a payment reader that uses the payment data in order to request a payment transaction. Such wearable payment device may be conveniently carried by and accessible to the user such that utilization of the payment device for the payment transaction is less burdensome for the user, thereby encouraging use of the payment device for payments. Indeed, in some cases, such as when the payment device is implemented as a finger ring or other type of jewelry, the user may be encouraged to carry the payment device in an exposed manner such that it is readily available for the payment transaction without the user having to search in a wallet, pocket, or purse.

Abstract: A wearable payment device, such as a finger ring worn by a user, communicates payment data to a payment reader that uses the payment data in order to request a payment transaction. Such wearable payment device may be conveniently carried by and accessible to the user such that utilization of the payment device for the payment transaction is less burdensome for the user, thereby encouraging use of the payment device for payments. Indeed, in some cases, such as when the payment device is implemented as a finger ring or other type of jewelry, the user may be encouraged to carry the payment device in an exposed manner such that it is readily available for the payment transaction without the user having to search in a wallet, pocket, or purse.

Abstract: A wearable payment device, such as a finger ring worn by a user, communicates payment data to a payment reader that uses the payment data in order to request a payment transaction. Such wearable payment device may be conveniently carried by and accessible to the user such that utilization of the payment device for the payment transaction is less burdensome for the user, thereby encouraging use of the payment device for payments. Indeed, in some cases, such as when the payment device is implemented as a finger ring or other type of jewelry, the user may be encouraged to carry the payment device in an exposed manner such that it is readily available for the payment transaction without the user having to search in a wallet, pocket, or purse.

Abstract: A system for sensing a proximity of a near field communication (NFC) device includes an NFC reader that communicates with a remote NFC device through load modulation. The NFC reader transmits a wireless carrier signal from an antenna, and the remote NFC device modulates such carrier signal by changing its internal impedance in order to transmit data to the NFC reader. The NFC reader has at least one antenna for receiving the modulated signal. This antenna is coupled to circuitry that measures a spectrum of the received signal and identifies a resonant frequency of the NFC device based on the measured spectrum. Such circuitry also determines the signal's amplitude at such resonant frequency and precisely estimates the distance of the remote NFC device from the reader based on such amplitude.

Abstract: A wireless communication device communicates with an inductively coupled device via a wireless carrier signal that may be modulated by both the wireless communication device and the inductively coupled device. The inductively coupled signal is transmitted from a transponder antenna of the wireless communication device. The wireless communication device also includes an auxiliary antenna. The auxiliary antenna is enabled while the wireless communication device is receiving a modulated version of the wireless carrier signal from the inductively coupled device.

Abstract: A wireless communication device communicates with an inductively coupled device via a wireless carrier signal that may be modulated by both the wireless communication device and the inductively coupled device. The inductively coupled signal is transmitted from a transponder antenna of the wireless communication device. The wireless communication device also includes an auxiliary antenna. The auxiliary antenna is enabled while the wireless communication device is receiving a modulated version of the wireless carrier signal from the inductively coupled device.

Abstract: A wireless communication device has a display device and a transmitter that wirelessly transmits a wireless (e.g., NFC) signal from an antenna. The antenna is positioned such that the display device may be between the antenna and another wireless communication device that is to receive the signal, and the display device may attenuate such signal. A reflector of the display device is patterned with small gaps in order to limit the loop sizes of eddy currents that are induced by the wireless signal, thereby reducing parasitic power consumption of the reflector to the wireless signal. Thus, the presence of the gaps in the reflector improves the transparency of the display device to the wireless signal without significantly affecting the performance of the reflector in sinking heat and reflecting light.

Abstract: A payment reader includes a tuning circuit that provides a tuned transmission source signal to an antenna for transmission. A sense circuit coupled to the antenna provides a measured transmitted signal to a binary phase detection circuit. The binary phase detection circuit filters and processes the signal to provide an analog phase signal that corresponds to a phase difference between the measured transmitted signal and the transmission source signal. A comparison circuit compares the analog phase signal to a reference signal, and a decision circuit adjusts the operation of the transmission circuitry based on the comparison.

Abstract: A multi-layer antenna for near-field communications can have a first layer on a top surface of flexible circuit board and a second layer on a bottom surface of the flexible circuit board. The first layer and the second layer can be connected in series by a through connection in the flexible circuit board. The first layer can incorporate a single loop in the shape of a rectangle and the second layer can incorporate a single loop in the shape of a rectangle. The second layer of the antenna can be vertically aligned with the first layer of the antenna and can have current flow in the same direction as the first layer to provide for an increased magnetic flux from the antenna.

Abstract: A communication device has a processing unit, a transmit circuit, and an antenna. The processing unit generates a carrier signal and modifies the carrier signal based on a notch modulation procedure having notch delay and a notch width. The notch width is selected based on a desired modulation index. The resulting modulation signal is provided to the transmit circuit, which generates a wireless data signal that is transmitted by the antenna.