13757results about "Electromagnetic transmission" patented technology

The present invention provides a system for operating a power line communications system that employs surface wave communications and conducted communications. The system is comprised of a plurality of network elements, which may take the form of repeaters, communication interface devices, backhaul devices, medium voltage transducers, distribution points, aggregation points, and others. In one embodiment, surface waves are communicated over the medium voltage power lines and the conducted communications are communicated via the low voltage power lines to and from customer premises.

A pixel circuit having a function of compensating for characteristic variation of an electro-optical element and threshold voltage variation of a transistor is formed from a reduced number of component elements. The pixel circuit includes an electro-optical element, a holding capacitor, and five N-channel thin film transistors including a sampling transistor, a drive transistor, a switching transistor, and first and second detection transistors. The sampling transistor samples and supplies an input signal from a signal line so as to be held into the holding capacitor. The driving transistor drives the electro-optical element with current in response to the held signal potential. The first and second detection transistors detect a threshold voltage of the drive transistor and supply the detected voltage into the holding capacitor in order to cancel an influence of the threshold voltage in advance.

The purpose is to fix a portion of a living body, which is an object of measurement, stably without strain and to acquire accurate inspection results with good reproducibility. An apparatus for capturing an image of a living body includes: a base for mounting a portion of a living body to be inspected; two sidewall members capable of holding the mounted portion of the living body therebetween from both sides; a light source section for supplying a light to the portion of the living body held on the base and between the sidewall members; and a light receiving section for detecting optical information from the portion of the living body supplied with the light, and a non-invasive apparatus for living body inspection including the above apparatus for capturing an image of a living body in which the light receiving section includes an image capturing element, and an analyzing section for calculating information on blood flowing through a blood vessel by analyzing an image of a tissue including the blood vessel obtained by the image capturing element.

The method and apparatus for information conveyance and distribution to bidirectionally focus or guide a wide spectrum of electromagnetic waves propagated over a possible variety of propagation media, including free space or wireless, surface wave, and cable or wired transmission lines. The apparatus communicates with information devices immediately adjacent to these media wherein the devices, which are not themselves part of the apparatus, may have electromagnetic access to one another. The apparatus maintains adequate signal to noise ratio and low distortion for a possible variety of different signal modulation and encoding types which it can support while permitting transparent, simultaneous communications among a variety of devices. Spread spectrum techniques may be used within the apparatus to mitigate propagation medium distortions and impairments as well as to control access and provide a means for securing information within the corridor and for obtaining revenue. Adapters may be employed to provide either full or half duplex access to the information devices which utilize it.

The system includes, at least first and second antennas receiving first and second radio frequency signals, and a multiplexing system converting the first and second radio frequency signals to first and second optical signals and multiplexing the first and second optical signals for transmission over the optical fiber. A central processing base station is adapted for connection to the optical fiber. The central processing base station demultiplexes the first and second optical signals from the optical fiber, converts the first and second optical signals into the first and second radio frequency signals, and processes the first and second radio frequency signals to obtain information signals. In another embodiment, a conductor such as a coaxial cable replaces the optical fiber, and the multiplexer multiplexes the first and second radio frequency signals onto the conductor. In a further embodiment, the central processing base station uses the same techniques to send signals to an access point for transmission.

A remote control uses IR (infrared) commands to control various consumer appliances made by various manufactures. The remote control is low-cost, consumer-friendly, programmable, has its own graphical display so it does not interfere with a TV or other viewing screen, and is capable of interacting with the internet or other data source to provide a rich set of functionality.

A hybrid cable comprising an optical fiber, an intermediate layer surrounding the optical fiber, and an electrically insulating jacket surrounding the intermediate layer. The intermediate layers include a collection of metallic strands. The hybrid cable may be used to establish simultaneous electrical and fiber-optic connection between two communication devices. Thus, the two communication devices may simultaneously transfer optical signals through the optical fiber and perform any of various electrical functions (power transfer, eye safety control) through the metallic strands. For example, an optical transceiver may couple to an optical antenna unit through the hybrid cable. Such an optical transceiver may serve as part of a point-to-point link, a point-to-multipoint link, and/or, a link between a primary transceiver unit and an optical router.

Provided is a electric power transmitting apparatus (300) that has sub-electric power transmission mode, and main electric power transmission mode for transmitting power larger than that transmitted in the sub-electric power transmission mode. A power transmitting unit (310) transmits power in a wireless manner. A electric power transmission control unit (320) controls, in sub-electric power transmission mode, power to be transmitted by means of the power transmitting unit (310) and transmission timing of the electric power transmission such that at least power that the electric power receiving apparatus needs to transmit power request notification is transmitted at random intervals. A electric power transmission control unit (320) performs switching to the main electric power transmission mode, in the cases where a communication unit (350) acquired the power request notification transmitted from the electric power receiving apparatus.

Delivery catheters and systems are adapted for delivering multiple discreet prostheses in body lumens. An exemplary delivery catheter comprises a sheath, a pusher for moving the prostheses relative to the sheath, and a valve member for selectively retaining the prostheses in the sheath. For balloon expandable stents, an elongated shaft and an expandable member are slidably disposed in the sheath, and the prostheses are positionable on the expandable member for deployment in the body lumen. The valve member allows a selected number of prostheses to be deployed from the sheath while retaining other prostheses within the sheath.

The invention relates to a monitor for monitoring at least one optical signal parameter in an opticl fibre having an access region of reduced cladding sufficient to allow access to the evanescent field. The monitor includes an optical element mountable adjacent to the access region of an optical fibre which optical element is capable of obtaining access to the evanescent field to enable use of the data therein to derive the at least one optical signal parameter.

A coupling circuit arrangement for data communication over a power line comprises a modulator/demodulator circuit for modulating data signals for transmission over the power line, and for demodulating signals which have been transmitted over the power line into data signals, a power supply circuit, and isolation means for providing galvanic isolation from the power line. The isolation means comprises light emitting elements and light detecting elements, which are arranged between the modulator/demodulator circuit and the power line. The isolation means may also be used to transmit a digital control signal which indicates the status of the power supply circuit or an over-temperature condition, or which is a transmit enable signal. The digital control signal may be encoded in the analog data signal by a digital shift in the DC bias level or by a complete removal of the DC biasing signal.

The present invention allows remote antenna units for radio frequency signal transmission and receipt to operate without the requirement for remote electrical power supplies or for connecting cables that incorporate electrical conductors. According to an aspect of the present invention, an optical communications system employing radio frequency signals comprises a central unit; at least one remote unit having at least one optoelectronic transducer for converting optical data signals to radio frequency signals and converting radio signals to optical signals and at least one antenna to receive and send radio frequency signals; at least one optical fiber data link between the central unit and the remote unit for transmitting optical data signals therebetween; and at least one optical fiber power link between the central unit and the remote unit for providing electrical power at the remote unit.

A dual-band antenna is provided that combines two normally disparate communications modes into a single compact aperture minimizing overall mass and volume, while maintaining high performance efficiency and reciprocity of each individual mode. The antenna is compatible with both optical (near-IR/visible) and RF (microwave/millimeter-wave) transceiver subsystems for high bandwidth communications, applicable primarily to long- to extremely long-range (space-to-ground) link distances. The optical link provides high bandwidth while the RF provides a lower data-rate weather backup, accommodation for traditional navigation techniques, and assistance in cueing the extremely tight optical beam by matching the RF beamwidth to an optical fine-steering mechanism field-of-regard. The configuration is built around a near-diffraction-limited high performance primary mirror shared by both a direct-fed RF antenna design and a Cassegrain optical telescope. Material properties are exploited to combine the optical secondary mirror with the RF feed structure, providing a collimated optical beam interface at the antenna vertex.

A communication system for distributing information via a network to one or more subscribers includes a multi-port switch, one or more radio frequency (RF) modems coupled to respective ports of the switch, a combiner and a transmitter. The switch forwards source information to the RF modems based on address information. Each RF modem modulates and up converts information from the switch to an RF signal within a respective subscriber channel of the television broadcast spectrum. Each channel is assigned to one or more subscribers, and each subscriber is allocated unshared bandwidth. Each channel may be further divided into unshared bandwidth increments, so that multiple subscribers may share a single channel. The combiner combines modulated information from each RF modem into a combined signal and the transmitter transmits the combined signal to the subscribers via the network. An HFC network including a distribution point and one or more optical nodes is contemplated, each optical node serving a particular geographic area via a corresponding coaxial cable. Each subscriber destination includes a gateway device or the like that is tuned to a corresponding channel to retrieve source information from that channel, and to deliver the information to one or more local subscriber devices. The gateway further includes converters, a modulator and an up converter to receive and transmit subscriber information upstream to the distribution point. The gateways and an address resolution server enforce point to point communications. A bandwidth manager allocates bandwidth and monitors bandwidth usage.

A universal remote controller having a radio frequency (RF) control mode for generating RF signals for controlling an RF based home automation system and having an infrared (IR) control mode for controlling an infrared based electronic device using IR control signals. Control information input via a user interface is used to generate the IR control signals in the IR mode of operation and is used to generate the RF signals in the RF mode of operation. A control unit controls overall operation of the universal remote controller including the generation of IR signals to control electronic devices with the IR signals. A home automation module is connected to the control unit via a communication interface to generate RF signals to control the RF based home automation system. A display displays feedback information to the user regarding operations for controlling the home automation system.

A digital distributed antenna system (DDAS) that regains the capability to perform simulcast to multiple simulcast groups while using a base station's direct digital output is provided. The User Plane data is adapted for simulcast and also for eliminating time delay ambiguities across multiple simulcast digital radios. In addition, the Control and Management Plane is aggregated across multiple remote units to allow a non-modified donor digital base station to control simulcast groups. The result is a low cost digital DAS that can efficiently distribute the capacity of a digital base station to solve coverage and capacity requirements in a manner similar to that now accomplished using a traditional base station with RF in/out.

A network is provided that includes a plurality of antennas coupled over the network to a plurality of base stations. The network can be optical or constructed with RF microwave links. The base stations are configured to provide cellular transmission. A plurality of links couple the plurality of antennas and the plurality of base stations. At least one link of the plurality of links provides multiple transmission paths between at least a portion of the base stations with at least a portion of the antennas. In one implementation, at least one link of the plurality of links is shared by at least two cellular operators on different transmission paths. In another implementation, at least a portion of the plurality of base stations are in a common location and at least a portion of the antennas are geographically disbursed.