摘要:
An antenna comprising two essentially identical electrically conducting rectangular plates lying in parallel planes and separated so that a gap is formed between the plates also includes a dielectric situated within the gap and exhibiting a relative permittivity that changes with frequency. Electrical connectors connect the plates to corresponding conductors that carry the signal to be radiated by the antenna.
摘要:
An ultra-wideband (UWB) communications system combines the techniques of a transmitted reference (TR) and a multiple access scheme called delay hopping (DH). Combining these two techniques using UWB signaling using a continuous noise transmitted waveform avoids the synchronization difficulties associated with conventional approaches. This TR technique is combined with the DH multiple access technique to create a UWB communications scheme that has a greater multiple access capacity than does the UWB TR technique by itself.
摘要:
An integrated tracking, telemetry and local area networking system is provided. A communications system comprises a broadband subsystem comprising at least one UWB node including a first UWB transceiver and at least one application node linked to the UWB node by a broadband link. The system further comprises a wireless subsystem comprising at least one remote communicator, the remote communicator including a second UWB transceiver. The first and second UWB transceivers are configured to communicate with each other via an UWB communications link.
摘要:
An apparatus and method for indicating whether a coupler of a locomotive is in a coupled or uncoupled state is provided. The apparatus comprising: an optical sensor positioned on a portion of the coupler, wherein the sensor provides a real-time signal indicative of either a coupled or an uncoupled state of a coupler, wherein the signal is transmitted wirelessly by a transmitter in operable communication with the sensor. The method comprising: providing a signal indicative of the presence or proximity of a second coupler to the first coupler, the signal being provided by an optical sensor configured to provide the signal as the state of the coupler has changed; transmitting the signal wirelessly to a controller; processing the signal with a control algorithm resident upon the controller; and providing visually perceivable indication of the position of the coupler.
摘要:
An electrical power generation system comprises a variable capacitor and a power source. The electrical power generation system is configured to generate electric power via movements of the rail. The power source is used in the form of a generator to prime the variable capacitor that effectively multiplies the priming energy of the power source by extracting energy from the passing vehicle. By alternately priming the variable capacitor using charge from the power source and discharging it at a later time in a cyclic manner to change the capacitance, a significantly large amount of electrical energy is produced due to change in capacitance than from the power source itself.
摘要:
A method and apparatus for nondestructive testing a railroad rail is provided. The method includes locating at least one magnetic exciter adjacent to the rail, the at least one magnetic exciter includes an emitting end and a longitudinal axis extending perpendicularly through the emitting end, discharging the energy storage circuit through the at least one magnetic exciter such that only a magnetic pulse enters the rail at a location of the exciter, and controlling a shape of the magnetic pulse. The apparatus includes at least one magnetic exciter adjacent to a rail, a energy storage circuit electrically coupled to the at least one magnetic exciter the energy storage circuit is configured to supply a shaped current pulse to the at least one exciter, and a power source electrically coupled to the energy storage circuit.
摘要:
A brevity signaling module for a digital television (DTV) receiver enables the reception of emergency broadcast messages. The overlay signal received at the receiver front end is squared in a squaring loop, producing spectral lines at DC and twice the overlay signal frequency, or 2&ohgr;, where &ohgr;=2&pgr;f and f is the center frequency of the overlay signal. The squared signal is passed through a narrow band filter having a bandwidth sufficient to pass a spectrum containing a plurality of tones 2&ohgr;, 2&ohgr;1, 2&ohgr;2, . . . , 2&ohgr;n, where 2&ohgr;1, 22, . . . , 2&ohgr;n are different frequency tones assigned to different auxiliary functions. The detected tone is used by a control module to determine whether normal multipath processing should be performed or whether this processing should be suppressed and auxiliary functions performed, including turning on the DTV receiver power in order that an emergency broadcast message might be conveyed to persons in the vicinity of the DTV receiver.
摘要:
A digital television (DTV) receiver is provided with a sounder comprising a wideband transmitter and a plurality of wideband receivers having separately located receiving antennas, so that the sounder is, in effect, a bistatic radar system for any given channel, in order to characterize a significant nearby, indoor reflector. A microprocessor receives the timing information generated by the wideband transmitter impulses and the reflected impulse returns to each of the receiving antennas, and calculates a multipath model representing the three-dimensional location of a significant, nearby scatterer.
摘要:
A system for spread spectrum power line communications employs a harmonic modulation (HM) transmitter coupled to the power line for transmitting message bits to an HM receiver. The spread spectrum accommodates a plurality of HM transmitters simultaneously occupying the same bandwidth. The spectrum of HM, in a frequency range above 60 Hz but below the maximum frequency that will carry through a distribution transformer, is ideal in combating carrier synchronous noise since it can be interleaved with the noise harmonics and therefore be effectively spectrally disjoint with the synchronous noise process spectrum.
摘要:
The condition and/or integrity of goods is monitored while in transit using a local area network of tracked assets. Autonomous electronic sensors are situated in proximity to the cargo being shipped. These sensors communicate with an asset tracking unit affixed to the container for the goods via a mutter mode transceiver. The tracking unit has the ability to relay the cargo sensor data to the central station on demand, on exception, or on a predetermined schedule established by the central station. Communication between the cargo sensors and the tracking unit may be one-way (i.e., sensor to tracking unit) or two-way. Multiple sensors may communicate with each tracking unit.