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.

A noncontact communication medium includes a processing circuit that is mounted on a substrate on which an antenna coil is formed, and has an internal capacitor, and an external capacitor that composes a resonance circuit configured to resonate at a predetermined resonance frequency, along with the internal capacitor and the antenna coil. A method for manufacturing a noncontact communication medium includes measuring a temporary resonance frequency in a state in which the external capacitor is not connected to the processing circuit and in a state in which the processing circuit is connected to the antenna coil, and deciding capacitance of the external capacitor based on a degree of difference between a reference resonance frequency in a case where the noncontact communication medium performs communication with an outside through a magnetic field and a temporary resonance frequency.

Near field communication (NFC) methods, systems, and devices are disclosed herein. In an example embodiment, the method includes providing a first NFC device including a NFC antenna, and transmitting a radio frequency (RF) signal including a RF carrier signal by way of the NFC antenna. Also, the method includes receiving a first resonant signal after the transmitting has ceased, and processing the first resonant signal to generate a first portion of transformed signal information. Further, the method includes identifying one or both of a first state and a first event based at least in part upon or associated with the first portion of the transformed signal information.

A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna to receive a high frequency signal, a capacitor bank coupled with the antenna, a charge pump coupled with the antenna configured to convert the high frequency signal to a direct current (DC) signal, an envelope detector to measure peak voltage of the high frequency signal and a detector to compare an output of the charge pump and an output of the envelope detector. The RFID tag also includes an impedance tuning circuit coupled with the charge pump and the envelope detector configured change a capacitance of the capacitor bank based on an output of the detector and the envelope detector.

A mobile device includes a smartcard controller that does not rely on power received from an interrogating RF field. The mobile device also includes a small inductive device capable of inductive coupling with an RFID reader. The smartcard controller includes circuitry to modulate an impedance of a port coupled to the inductive element when in the presence of an interrogating RF field at substantially 13.56 MHz.

A noncontact communication medium includes a processing circuit mounted on a substrate having a coil to induce power by action of an external magnetic field applied from an outside, and processing circuit having an internal capacitor; and an external capacitor externally attached to the processing circuit. The external capacitor, the internal capacitor, and the coil constitute a resonance circuit resonating at a predetermined resonance frequency by the action of the external magnetic field. The external capacitor is connected in parallel with the internal capacitor, and the resonance circuit has a Q-value determined in accordance with a characteristic of the external capacitor.

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.

A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna to receive an input AC signal and a tuning system coupled with the antenna to optimize signal strength of the input AC signal. The tuning system includes a charge pump rectifier. A diode rectifier is included and is coupled with the antenna to receive the input AC signal after the tuning system optimizes the signal strength by tuning input impedance of the antenna.

A device for managing operation of an object capable of contactless communication with a reader magnetically coupled to the object includes a modulator configured to modulate an impedance of a load connected across terminals of an antenna of the object during a transmission phase during which information is transmitted from the object to the reader. The device further includes a monitor configured to carry out a monitoring phase, prior to the transmission phase. The monitoring phase includes a test modulation of the impedance of the load, a monitoring of a level of amplitude modulation of a modulated test signal present at the antenna of the object and resulting from the test modulation, and a capacitive modification of the impedance of the load if this level is lower than a threshold.

Embodiments disclosed generally relate to a wireless identification tag with a response time that varies as a function of incoming signal frequency and system and methods for use thereof. In one implementation, the tag may include at least one antenna tuned to receive energy transmitted at a first frequency and at a second frequency. The tag may also include at least one transmitter. The tag may also include at least one circuit configured to detect whether energy is received in the first frequency or the second frequency, and to cause the at least one transmitter to transmit an immediate response when the second frequency is detected and to transmit a delayed response when the first frequency is detected.