A wearable device is described that is configured to alert a subject prior to encountering an obstacle. The subject may be visually-impaired. The device includes: a mobile transceiver tag adapted to be worn by a subject within a designated area (e.g., a swimming pool); three or more stationary transceiver beacons in spaced apart, fixed positions; a wearable signal output device (e.g., headset); and a processor with software that can calculate the subject's position relative to one or more obstacles (e.g., end of swimming lane) and sends a left, right, or reverse signal to the signal output device.

In one aspect, an electronic device for continuous and simultaneous powering and data transfer is provided, the electronic device comprising: an inductive power receiver operable to generate a power signal from a sensed magnetic field, the power signal; an LC tank and diode pair electrically coupled to the power receiver and operable to obtain the power signal, the LC tank and diode pair cooperating to generate a corresponding clipped signal thereof; and an antenna comprising a high-pass filter, the antenna electrically coupled to the diode pair and operable to emit a pulse-train by high-pass filtering the clipped signal.

Disclosed are a method and a device for measuring a biometric signal by using a radar. The disclosed method measures a plurality of biometric signals by using a radar by: (a) receiving the plurality of biometric signals from the radar; (b) calculating distance information of the received plurality of biometric signals and classifying the same on the basis of a distance; (c) selecting a signal having a largest variance according to a time; (d) further selecting a number of signals among signals having a distance with the signal selected in the step (c) smaller than an arbitrary distance from the distance-based classified signals; (e) converting all signals selected from a time domain to a frequency domain; (f) calculating a reliability of each biometric signal from the converted distance-based signals; and (g) detecting a corresponding biometric signal by selecting the distance-based signal where the calculated reliability is highest.

Methods are provided for UWB ranging based on contention-based multiple access. A method performed by a first UWB device includes transmitting an IM for initiating UWB ranging, receiving an AM from a second UWB device within a contention period, transmitting a first RM, receiving a second RM corresponding to the first RM from the second UWB device, and transmitting an FM.

The present disclosure relates to an apparatus and method for synthetically making an ultra-wide imaging bandwidth in millimeter-wave frequencies, resulting in improved image resolutions to values previously unattained. The synthetic approach sums up a number of available sub-bands to build an unavailable ultra-wideband system. Each sub-band contains a transceiver unit which is optimized for operation within that specific sub-band. The number and position of the sub-bands can be adjusted to cover any frequency range as required for the specific application.

A method for providing bi-directional ultra-wide band (UWB) ranging is provided. The method by a first ultra-wide band (UWB) device includes transmitting an initiation message for initiating UWB ranging, receiving at least one device access message from at least one second UWB device within a contention period, transmitting at least one reply message, receiving at least one device reply message corresponding to the at least one reply message from one or more of the at least one second UWB device, and transmitting, to the one or more second UWB device, a final message based on UWB ranging performed using the device access message, the reply message, and the device reply message.

A fall detection system includes a radar that generates emitting radio waves and receives reflected radio waves from a person under detection, a data generator that generates a point cloud according to the reflected radio waves, an area determining device that determines a sub-area of a detecting area in which the person under detection lies, and a classifier that determines whether the person under detection falls according to the point cloud. The classifier adaptively processes the point cloud with different methods according to sub-areas as determined by the area determining device respectively to determine whether the person under detection falls.

A system and method providing a radar-based motion-sensing user interface suitable for issuing commands to a device or system as a consequence of the detection of user motion, whole-body gestures and/or hand gestures. The system and method derive a three-dimensional representation of a user within a defined space from two-dimensional data obtained from multiple reflected radar signals. The three-dimensional representation is then processed to recognize a human body, and in particular the movement and/or position of the body and/or body parts and joints. The recognized movement and/or position are then compared to a known list of gestures and movements that are associated with particular device/system commands. If one or more of the recognized movements and/or positions conforms with a command movement/gesture, the associated command is issued to the device or system being controlled.

An ultra-wideband dual-polarized tightly coupled bowtie antenna array for ground-based polar ice sounding radar is described. The antenna array has a very large effective aperture to increase the directivity. At the same time, it is lightweight and low profile to minimize the payload and maximize the survey range. In an implementation, the antenna array operates between 180-620 MHz with a fractional bandwidth of 3.4:1. The broadband performance benefits from the tightly coupled antenna elements. A feature of the antenna array is the planar feeding structure without balun. The antenna array element has the microstrip feeding line integrated with one arm of the bowtie antenna. The other arm is directly fed by the microstrip line. By adding a ferrite core around the coax cable for common mode suppression, the bowtie antenna element can be fed differentially without using bulky vertical feeding structure and balun.

A method for generating ultrawideband pulsed microwave signals from optical field ionization of a gas with an ultrashort laser pulse, where the amplitude and frequency of the signals can be controlled via the characteristics of the laser pulse and/or the gas. The center frequency of the spectrum of the microwave signal can be controlled by changing the laser pulse energy. The amplitude of the microwave signal can be controlled by changing the wavelength of the laser pulses. The amplitude and frequency of the microwave signal can be tuned by controlling the pressure of the gas medium. The location at which the microwave signal is generated can be controlled by controlling the location at which the laser pulse creates a plasma. Interference among microwave signals resulting from multiple laser-produced plasmas can be used to construct an ultrawideband microwave signal having a predetermined amplitude and frequency.