Some embodiments provide a system for charging devices. The system includes a master device and a slave device. Some embodiments provide a method for charging devices in a system that includes a slave device and a master device. The slave device includes (1) an antenna to receive a radio frequency (RF) beam and (2) a power generation module connected to the antenna that converts RF energy received by the slave antenna to power. The master device includes (1) a directional antenna to direct RF power to the antenna of the slave device and (2) a module that provides power to the directional antenna of the master device.

Method and apparatus for wirelessly transferring power and communicating with one or more slave devices

An ultrasound power transmitter comprising a transmit ultrasonic transducer array has a plurality of transmit ultrasonic transducers. The ultrasound power transmitter activates a set of transmit ultrasonic transducers in close proximity of an electronic device to be arranged to beam ultrasound energy to the electronic device. Alignment magnets of the ultrasound power transmitter are aligned with corresponding alignment magnets of the electronic device to manage the ultrasound beaming. The ultrasound energy may be converted into electric power to charge the battery of the electronic device. Feedbacks may be provided by the electronic device to the ultrasound power transmitter to increase power transmission efficiency. The ultrasound power transmitter may pair the electronic device with other different electronic devices utilizing ultrasonic signals. A spacer with good ultrasound power transmission properties may be located between the ultrasound power transmitter and an ultrasound power receiver of an intended electronic device to enhance power transmission.

Method and system for wireless battery charging utilizing ultrasonic transducer array based beamforming

Optical fiber-based wireless systems and related components and methods are disclosed. The systems support radio frequency (RF) communications with clients over optical fiber, including Radio-over-Fiber (RoF) communications. The systems may be provided as part of an indoor distributed antenna system (IDAS) to provide wireless communication services to clients inside a building or other facility. The communications can be distributed between a head end unit (HEU) that receives carrier signals from one or more service or carrier providers and converts the signals to RoF signals for distribution over optical fibers to end points, which may be remote antenna units (RAUs). In one embodiment, calibration of communication downlinks and communication uplinks is performed to compensate for signal strength losses in the system.

Optical fiber-based distributed antenna systems, components, and related methods for calibration thereof

Embodiments of the present invention include a method of determining a location of a mobile device. The method comprises transmitting a signal between a plurality of known locations and receiving signal at device of unknown location such as a mobile device. The signal may include multiple tones having different frequencies and resulting in sets of residual phase differences. The location of the mobile device may be determined using the known locations and the frequency and phase differences between the transmitted tones. In one embodiment, OFDM signals may be used between an access point and mobile device, for example, to determine the location of the mobile device.

Methods and systems for determining the location of an electronic device using multi-tone frequency signals

Embodiments of the present invention include radio frequency identification location systems and methods. In one embodiment, RF signals are transmitted from one or more RFID readers, and in accordance therewith, backscattered signals are received from a tag to be located. A plurality of measured position parameters are used to determine a location of the tag. In one embodiment, one reader may transmit and three readers may receive signals to determine the position of a tag. In other embodiments, multiple readers may transmit and receive. In another embodiment, one reader may transmit from different positions to locate a tag. Embodiments of the invention may be used to track a moving tag. A reader's position may be determined using GPS, reference tags, or the reader may be positioned in a known location. A map may be provided to a user to display the location or movement of a tag or a corresponding item.

RFID location systems and methods

A bidirectional radio frequency identification (RFID) network system and method are presented. The system allows users to configure, monitor, and manage different sensor devices by using a graphical user interface real-time. The reconfiguration is done through a network management computer at the top system level that receives user input, generates code images according to the user input, and appropriately routes the code images to sensor routers that directly control the sensors. If the system is multi-layered, some code images are also sent to the intermediate-level network management computers. The system allows users to not only monitor a business flow but react to problematic situations quickly by adjusting the workflow. The aspect-oriented nature of the system allows users to reconfigure the system based only the Functionality aspects without worrying about the Partitioning aspects (e.g., how the network and the sensors are physically connected).

Radhika Muralidharan

Papers

Radio Frequency Identification (RFID) Network System and Method