Abstract: A system includes a signal processing unit including an antenna configured to receive a radio frequency signal as a received radio frequency signal, and a baseband amplifier coupled to the antenna. The system includes a processor configured to cause the communication unit to stop generating a radio frequency polling signal, set an amplification gain of the baseband amplifier to a first gain value, periodically record, at a sample rate, an indication of a magnitude of the amplified radio frequency signal to generate a plurality of sample values, at a predetermined time interval after the communication unit stopped generating the radio frequency polling signal, set the amplification gain of the baseband amplifier to a second gain value, and transmit the plurality of sample values to a classifier module to determine whether the radio frequency signal is received from a near-field communication-enabled device.

Abstract: For a mobile device having a main battery and a backup power source, a method is provided for wirelessly charging the backup power source using a reader when the main battery of the mobile device is fully depleted and unable to provide enough power for an RF transaction. The reader detects the mobile device cannot perform the RF transaction. In response, the reader generates an RF field that provides charge for the backup power source of the mobile device. After charging is complete, the mobile device performs the RF transaction using the charged backup power source. In one embodiment the mobile device is a mobile phone being used as a digital key and the reader is implemented in a smart door handle of an automobile that is unlocked by the RF transaction.

Abstract: A near-field communication (NFC) device is configured to track the amplitude associated with a received radio frequency (RF) signal while transmitting a different RF signal indicating a command. To this end, the NFC device includes tracking circuitry configured to track the amplitude associated with the received RF signal based on a modulation state indicated by a modulation envelope associated with the transmitted RF signal. In response to the modulation envelope indicating a modulated state, the tracking circuitry enters an idle state and does not track the amplitude associated with the received RF signal. In response to the modulation envelope indicating an unmodulated state, tracking circuitry tracks the amplitude associated with the received RF signal.

Abstract: A device may include a data storage device storing a first look-up table that contains a plurality of distance mappings that each associate a value of a first signal feature with a distance value. An NFC reader is configured to communicate with an NFC tag includes: an antenna, a transmitter that is configured to use the antenna to transmit a radio frequency transmitted field, a receiver configured to receive from the antenna one or more response signals in response to the radio frequency transmitted field transmitted by the transmitter, and a signal processor configured to: process the one or more response signals to determine a first value of the first signal feature, access the first look-up table to determine a first distance mapping that associates the value of the first signal feature with a first distance, and generate an output signal based upon the first distance.

Abstract: In accordance with a first aspect of the present disclosure, a communication device is provided, comprising: a front-end configured to receive an analog input signal, wherein the front-end comprises an analog-to-digital converter configured to convert the analog input signal into a digital signal; a digital signal processor configured to receive and process said digital signal; wherein the front-end further comprises a compressor operatively coupled to an input of the analog-to-digital converter, wherein said compressor is configured to apply a compressor function to the analog input signal before said analog input signal is provided to the analog-to-digital converter. In accordance with a second aspect of the present disclosure, a corresponding method of operating a communication device is conceived.

Abstract: A method and wireless device with a counterpart presence detector is provided. The detector includes only memory and logic circuits to detect a change in a ringing artifact from the presence of a RF device. The memory stores template signals and threshold values. The template signals may be generated using a metal object positioned various distances from the RF device. The ringing artifact, also called an RF-off signal, is sampled. A difference between subsequent ringing artifact samples is taken to produce a ringing artifact difference. Also, a difference between subsequent samples of a template signal is taken to produce a template difference. A Euclidean distance between the ringing artifact difference and the template difference is determined. The distance is compared to a threshold value. A presence of another RF device within the RF field of the RF device is detected if the distance compares favorably to the threshold value.

Abstract: A scalable reconfigurable intelligent surface (RIS) includes a plurality of RIS elements. The RIS elements include: a radio frequency identification (RFID) chip that powers the RIS element; a RFID antenna connected to the RFID chip; a RIS variable impedance controlled by the RFID chip; and a RIS antenna connected to the RIS variable impedance. The plurality of RIS elements produces a reflection beam that may be directed to a specific location. The RFID chip receives steering information to steer the reflection beam.

Abstract: Methods for operating a communications device that communicates via inductive coupling, methods for operating an NFC device, and a communications device that communicates via inductive coupling are disclosed.

Abstract: A sensor node is provided having a radio frequency (RF) circuit and a sensor interface circuit. The RF circuit wirelessly harvests energy from an external device such as a smart phone to produce a voltage at an output to charge a storage capacitor. The sensor interface circuit is configured to communicate with a sensor. In response to a request from the external device, the sensor node provides a voltage level of the capacitive element to the external device. The external device uses the voltage level to determine capabilities of the sensor node and to control sensing functions of the sensor node. In another embodiment, a method is provided to operate the sensor node.

Abstract: An energy harvesting unit includes a plurality of antennas configured to receive one or more signals and a plurality of first charge pumps, in which each of the first charge pumps is operatively coupled to one of the antennas, thereby forming pairs of antennas and first charge pumps. The energy harvesting unit also includes a selection unit configured to measure and compare output voltages of the first charge pumps and to select, from the antennas, a specific antenna. The specific antenna is coupled to the first charge pump that produces the highest output voltage. The energy harvesting unit also includes a multiplexer configured to couple the specific antenna selected by the selection unit to a second charge pump.

Abstract: A system includes a signal processing unit including an antenna configured to receive a radio frequency signal as a received radio frequency signal, and a baseband amplifier coupled to the antenna. The system includes a processor configured to cause the communication unit to stop generating a radio frequency polling signal, set an amplification gain of the baseband amplifier to a first gain value, periodically record, at a sample rate, an indication of a magnitude of the amplified radio frequency signal to generate a plurality of sample values, at a predetermined time interval after the communication unit stopped generating the radio frequency polling signal, set the amplification gain of the baseband amplifier to a second gain value, and transmit the plurality of sample values to a classifier module to determine whether the radio frequency signal is received from a near-field communication-enabled device.

Abstract: Methods for operating a communications device that communicates via inductive coupling, methods for operating an NFC device, and a communications device that communicates via inductive coupling are disclosed.

Abstract: In accordance with a first aspect of the present disclosure, a system is provided, comprising: a user device to be monitored for unauthorized displacement, an ultra-wideband (UWB) communication unit configured to set up a UWB communication channel with an external localization device and to perform at least one localization operation through said UWB communication channel, and a processing unit configured to detect said unauthorized displacement of the user device by analyzing an output of said localization operation. In accordance with a second aspect of the present disclosure, a localization device is provided, comprising: an ultra-wideband (UWB) communication unit configured to set up a UWB communication channel with an external system and to perform at least one localization operation through said UWB communication channel, and a processing unit configured to detect an unauthorized displacement of a user device comprised in said external system by analyzing an output of said localization operation.

Abstract: A sensor node is provided having a radio frequency (RF) circuit and a sensor interface circuit. The RF circuit wirelessly harvests energy from an external device such as a smart phone to produce a voltage at an output to charge a storage capacitor. The sensor interface circuit is configured to communicate with a sensor. In response to a request from the external device, the sensor node provides a voltage level of the capacitive element to the external device. The external device uses the voltage level to determine capabilities of the sensor node and to control sensing functions of the sensor node. In another embodiment, a method is provided to operate the sensor node.

Abstract: In accordance with the first aspect of the present disclosure, an ultra-wideband communication node is provided, comprising: an ultra-wideband communication unit configured to transmit one or more ultra-wideband frames to an external device; a processing unit configured to determine scrambled timestamp sequences for said ultra-wideband frames; wherein the processing unit is further configured to determine designated time slots, within which said scrambled timestamp sequences are to be received by said external device.

Abstract: 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.

Abstract: There is described a method of determining a phase value for an NFC card emulating device that enables said NFC card emulating device to communicate in phase with an NFC reader device while utilizing active load modulation, wherein the NFC card emulating device comprises a card antenna and the NFC reader device comprises a reader antenna, the method comprising receiving a reader signal from the NFC reader device at the NFC card emulating device through coupling of the card antenna and the reader antenna, the reader signal comprising a subcarrier modulation; estimating a resonance frequency of a system corresponding to the coupled card antenna and reader antenna based on the received communication signal; and determining the phase value based on the estimated resonance frequency and a set of parameters that represents a predetermined reference system. Furthermore, an NFC card emulating device, an NFC system, and a computer program are described.

Abstract: 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.

Abstract: In accordance with a first aspect, a communication device is provided, comprising: a transmitter configured to transmit one or more radio frequency signal pulses to an external communication device; a receiver configured to receive one or more response signals in response to the radio frequency signal pulses transmitted by the transmitter; a signal analyzer configured to detect one or more characteristics of the response signals, to compare the detected characteristics with predefined reference characteristics and to generate an output indicative of a result of comparing the detected characteristics with the predefined reference characteristics; a processing unit configured to determine at least one category to which the external communication device belongs based on the output generated by the signal analyzer. In accordance with a second aspect, a corresponding method of operating a communication device is conceived. In accordance with a third aspect, a corresponding computer program is provided.

Abstract: In accordance with a first aspect of the present disclosure, a channel equalizer is provided for use in a near field communication (NFC) device, the channel equalizer comprising: a filter configured to receive an input signal and to generate a filtered output signal; an estimator configured to determine filter coefficients to be used by said filter; a synchronizer configured to determine when to enable the channel equalizer and to provide one or more corresponding control signals to the estimator. In accordance with a second aspect of the present disclosure, a corresponding method of operating a channel equalizer for use in a near field communication (NFC) device is conceived.