158 results about "Rf radiation" patented technology

A wireless energy transfer system comprising: a transmitter configured to beam scan RF radiation across a plurality of sectors at a first frequency, a receiver storing energy from the RF radiation, and sending acknowledgements at a second frequency, the first frequency being significantly different from the second frequency, and a controller configured to direct wireless energy transfer from the transmitter substantially at the receiver based on the acknowledgements.

A wireless communications system optimizes performance by dividing communications functionality between a wireless pacemaker and a wireless monitoring base station according to the design constraints imposed by the system elements. Typical design constraints include high frequency operation, low pacemaker power consumption, reasonable range, high data rate, minimal RF radiation of internal circuitry, small pacemaker antenna system, simple pacemaker RF circuit design, high reliability, low pacemaker cost, and use of existing pacemaker construction methodologies.

An apparatus that includes a mobile phone detection system is provided. The apparatus comprises a wearable device having a pulse detection sensor, an RF detection sensor, and at least one processor. The pulse detection sensor is configured to detect a heart beat pulse of a body of a user wearing the wearable device. The RF detection sensor is configured to detect RF radiation signals from the body of the user wearing the wearable device. The processor may be operative responsive: to the pulse detection device detecting the pulse of the user; and the RF detection sensor detecting an RF radiation signal indicative of the user using a mobile phone; to output at least one notification signal indicative of the user using the mobile phone.

The invention provides a system (2) for non-invasive detection of the state of hydration in a living specimen, the system including an RF generator/transmitter (416) for emitting RF radiation signals and for transmitting the radiation signals through a tissue of a living specimen; an RF receiver (8) for receiving RF signals transmitted through the tissue, and for feeding the signals to a processor (10) for comparison of relative attenuation of RF frequencies passing through the tissue with a reference attenuation ratio signal, and an indicator unit (12) for providing an output signal representative of the water content level of the tissue. A method for non-invasive detection of the state of hydration in a living specimen is also described and claimed.

A broadband transceiver includes at least one layer structure that is substantially impermeable to RF radiation. The layer structure includes a first face surface substantially opposite a second face surface. A receive antenna is located proximate the first face surface and configured to receive RF transmissions. A transmit antenna is located proximate the second surface and configured to transmit RF transmissions. At least one of the receive and transmit antennas generates a generally toroidal radiation pattern that is stronger in a direction substantially parallel to the respective layer structure face surface compared to a direction substantially perpendicular to the face surface.

A method for increasing the interrogation range of an RF Tag in a radio communication system using RF Tags with multiple reflecting antenna elements. The reflecting antenna elements are predeterminately positioned, and preferably aligned, with respect to each other in the direction of expected incident RF radiation. The reflecting antenna elements are sequentially pulsed on and off such that while the first reflecting antenna element is in a signal reflecting operating state, the remaining reflecting antenna elements are in a substantially non-reflecting state, and when the second reflecting element is in a reflecting operating state, the remaining reflecting elements are in a non-reflecting state, etc. The sequential pulsing and predetermined fixed spacing between the reflector elements generates constructive interference between the reflected signals of the reflecting antenna elements which increases the power of the resulting reflected signal.

A method for concentrating radio frequency (RF) radiation on an object located in proximity to a reflector includes the steps of: selecting a target reflector and a level of power for conveying to the target reflector by reradiation from the target reflector, determining a resonance profile of the target reflector, the resonance profile including at least one resonant frequency of the target reflector, selecting a transmission profile matching the resonance profile, the transmission profile comprising the at least one resonant frequency, and transmitting RF radiation in accordance with the transmission profile towards the target reflector.

Field Image Tomography (FIT) is a fundamental new theory for determining the three-dimensional (3D) spatial density distribution of field emitting sources. The field can be the intensity of any type of field including (i) Radio Frequency (RF) waves in Magnetic Resonance Imaging (MRI), (ii) Gamma radiation in SPECT/PET, and (iii) gravitational field of earth, moon, etc. FIT exploits the property that field intensity decreases with increasing radial distance from the field source and the field intensity distribution measured in an extended 3D volume space can be used to determine the 3D spatial density distribution of the emitting source elements. A method and apparatus are disclosed for MRI of target objects based on FIT. Spinning atomic nuclei of a target object in a magnetic field are excited by beaming a suitable Radio Frequency (RF) pulse. These excited nuclei emit RF radiation while returning to their normal state. The intensity or amplitude distribution of the RF emission field g is measured in a 3D volume space that may extend substantially along the radial direction around the emission source. g is related to the 3D tomography f through a system matrix H that depends on the MRI apparatus, and noise n through the vector equation g=Hf+n. This equation is solved to obtain the tomographic image f of the target object by a method that reduces the effect of noise.

A device, system, and method for activating an ingestible imaging device with an RF radiation signal such that an imaging device that may be initially in a dormant state may be activated prior to ingestion by exposure to RF radiation The device may include an RF switch that may facilitate powering of one or more electrical components of the device when toggled. RF switch may also serve deactivate the ingestible imaging device.

A cellular communication system and method is described where a low-cost repeater is used to reduce the transmit power of a cell phone. The cell phone transmits a low-power modulated carrier signal to a nearby repeater. The repeater amplifies the signal and transmits it to a cellular base-station. The reduction of cell phone transmit power lowers the exposure of humans to RF radiation and increases the battery life of the cell phone.

A system and method for reading an RFID data tag comprising a plurality of diffractive elements being indicative of machine-readable data carried by the tag are provided. The diffractive elements have such shape that the dimension of the diffractive elements along one axis is substantially different than the dimension of the elements along the perpendicular axis. Each diffractive element is oriented in a direction other than the direction of its neighboring elements. The system comprises a transmitting antenna configured for emitting an RF radiation signal at a predetermined polarization towards the tag; and a receiving antenna configured for collecting re-radiated RF radiation produced by the tag in response to the RF radiation signal at a polarization orthogonal to the polarization of the transmitting antenna and generating electromagnetic signals indicative of the data carried by the tag. The system also includes an interrogator unit configured for generating the transmitted RF radiation signal and processing the electromagnetic signals produced by the receiving antenna for determining the data carried by the tag.

A compact antenna system can generate RF radiation fields having increased beamwidths and bandwidths. The antenna system can include one or more patch radiators. The lower patch radiators can be mounted to a printed circuit board that can include a ground plane which defines a plurality of slots. The slots within the ground plane of the printed circuit board can be excited by stubs that are part of the feed network of the printed circuit board. The slots, in turn, can establish RF radiation in a cavity which is disposed adjacent to the ground plane of the printed circuit board and a ground plane of the antenna system.

A cellphone or wireless phone device has separate components which are carried or mounted in corresponding parts of a hat, cap, or other headgear worn by the user. The cellphone microphone or voice pickup component, preferably as a unidirectional device, may be carried in the forward brim of a hat or visor of a cap, the antenna may be lined in the rear part of the hat or cap, the speaker earpiece may be attached to one or both sides of the hat, the keypad may be mounted between the fabric layers of the visor of a cap or the inner liner of a hat or headgear, and the electronic circuitry, including parts such as amplifier, signal processor and switcher, and battery may be mounted in an internal part or inner liner of the hat. Preferably, the sound receiving and reproducing is achieved using transducer membranes. The hat may have battery recharge pins or points exposed for attachment to an external recharging unit. A metallized RF-blocking layer may be provided on an inner layer of the hat to block RF radiation from the antenna from the user's head. A global position system (GPS) unit is preferably provided on the hat. A first liquid crystal display (LCD) is provided, preferably on the brim or visor, to show the time, channel, cell phone displays, text messaging and GPS latitude and longitude coordinates. A second LCD is provided and hinged on the underside of the brim or visor. The second LCD can be folded up flat when it is not in use or folded down directly in front of either or both the wearer's eyes when it is in use. The second LCD is provided to display video images and text information received and/or controlled with the keypad.

In a holographic surveillance system (10) for near real-time imaging of a target (15), a source of RF radiation directs a non-amplified reference beam of pulsed coherent RF electromagnetic radiation toward a target. An array of antennas (31) receives a reflected beam from the target together with a component of the reference beam so as to produce a signal representative of phase and amplitude data of received energy, and a processor (20) processes the signals so as to produce a holographic image for display on a display device coupled to the processor.

A radio frequency (RF) data carrier is presented. The RF data carrier comprises at least one diffraction element that has a dimension of the order of a wavelength of RF radiation and is responsive to RF irradiation, the response produced by the diffraction elements in the data carrier being indicative of machine-readable data carried by data carrier.