RFID readers may be configured to supply power to tags during frequency hops. When a reader is supplying power to a passive RFID tag via a first RF waveform having a first radio frequency and determines that it is to frequency-hop, the reader may determine whether the tag requires power during the hop. If so, the reader begins (or continues) to synthesize a second RF waveform with a second radio frequency while also synthesizing the first RF waveform, and frequency-hops by transitioning from transmitting the first RF waveform to transmitting the second RF waveform such that the power transmitted during the transition is sufficient for the tag to operate.

A wearable device includes a radio-frequency identification (RFID) tag having a memory that stores identification information. The wearable device also has a power harvesting circuit configured to harness power from electromagnetic radiation. Further, the wearable device has a sensor coupled to the power harvesting circuit and configured to utilize the power to monitor a condition of the wearable device. Even further, the wearable device has a microcontroller coupled to the sensor and configured to write data indicative of the condition to the memory of the RFID tag, wherein the RFID tag is configured to transmit the identification information and the data in response to receipt of the electromagnetic radiation from an RFID reader.

The present disclosure relates to a method for powering an electronic device. The electronic device includes at least one universal integrated circuit card or at least one secure element; at least one power supply circuit for said card or secure element; and at least one near field communication module. When the near field communication module changes from a standby or inactive state to an active state, the following successive operations are performed: —the components and circuits of said electronic device are started; —programs of the electronic device and said secure card or element are started at the same time.

The present disclosure relates to an electronic device comprising: at least one universal integrated circuit card or at least one secure element and at least one power supply circuit for said card or secure element, said power supply circuit being connected to at least a first power supply voltage source of the electronic device and comprising a voltage detector adapted to determine whether said first voltage source provides a first power supply voltage different from a reference voltage; and at least one near field communication module adapted to enter an active mode whenever said voltage detector determines that said first supply voltage is different from the reference voltage.

The system and techniques disclose herein describe a radio-frequency identification (RFID) capacitance liquid measurement and tag (RCLMT) system for detecting a volume of liquid in a container (liquid level detection), for example an amount of wine inside of a wine bottle. The RCLMT system includes a RFID chip, flexible printed circuit board (PCB), capacitive strips, and adhesive which implements a RFID tag-based sensor that advantageously uses low power and has low cost. Further, a user platform, including the RCLMT system and computer software applications (apps) and a backend system (e.g., cloud service) is described herein. The RCLMT system acts as a passive liquid level detection sensor, which enables the amount of a liquid beverage, such as alcohol, that is inside of a container to be automatically and accurately ascertained.

A circuit for a passive radio-identification tag operating in a UHF band is described, configured for a radio communication with a reader that emits a reading signal. The circuit is produced as a single chip, comprising one or more transducers for measuring a strain, a first sub-circuit configured for the acquisition of the transducer measurement, and a second sub-circuit configured for the radio transmission of the acquired measurement to the reader.

An electronic card with electronic function circuit includes a communication antenna for short-range wireless communication, a wireless communication IC electrically coupled to the communication antenna, a receiving coil, a resonant capacitor forming a receiving resonant circuit together with the receiving coil, a rectifying and smoothing circuit coupled to the receiving resonant circuit, receiving display elements, a power control unit that controls power from the receiving resonant circuit, and an electronic function circuit that operates by using the power from the receiving resonant circuit. In response to the receiving coil receiving the power, the power control circuit indicates a power receiving state to a user by driving the receiving display elements.

Systems and methods involving one or more wearable components that obtain information about a surrounding environment and provide information to a user to assist user in retrieving objects from the surrounding environment. The information may include navigation information related to a route that the user may take to retrieve an object, as well as information about the object to be retrieved. The wearable components may be include ones that may be mounted on the head of the user, as well as components that the user may wear on other parts of the body or that attach to clothing. The wearable components may include image sensors, microphones, machine-readable symbol readers, range-finders, accelerometers, and/or gyroscopes that may collect information from and about the surroundings of the user. The wearable components may also include one or more of a set of speakers and/or a display subsystem to provide information to the user.

An energy harvester and a method for tuning an antenna frequency of the energy harvester is provided. The energy harvester includes: a tuner circuit coupled to at least one antenna, wherein the tuner circuit includes at least one adjustable capacitor, wherein the at least one antenna is configured to harvest an electromagnetic ambient energy; a controller connected to the tuner circuit, wherein the controller is configured to control a voltage level within the energy harvester, wherein the controller is configured to iteratively set the at least one adjustable capacitor to tuning states until a best tuning state is set, wherein the best tuning state of the at least one adjustable capacitor substantially matches an antenna frequency and a frequency of the electromagnetic ambient energy; and a rectifier to convert the electromagnetic ambient energy to a direct current.

An LED sticker is disclosed that receives an NFC transmission from a nearby smartphone to energize LEDs in the sticker. A spiral (or loop) antenna is used in the sticker to generate power from the NFC transmission. The NFC signal is at 13.56 MHz, which is the resonant frequency of the NFC antenna circuit in the smartphone. The LED portion is formed by sandwiching pre-formed microscopic LEDs between two conductive layers to connect the LEDs in parallel. The conductive layers form a relatively large integral capacitor that is used to achieve the 13.56 MHz resonant frequency. So no additional capacitor is needed in the circuit to achieve a resonance of 13.56 MHz. This greatly reduces the design requirements of the antenna. The LED sticker may also contain an NFC tag having its own independent loop antenna and NFC chip. Various practical applications of the LED sticker are disclosed.