- 産業: Telecommunications
- Number of terms: 29235
- Number of blossaries: 0
- Company Profile:
ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standards for the information, entertainment and communications industry.
A wave produced by the interaction of time-varying electric and magnetic fields.
Industry:Telecommunications
A wave suitable for modulation by an information-bearing signal. 2. An unmodulated emission. Note: The carrier is usually a sinusoidal wave or a uniform or predictable series of pulses. Synonym carrier wave. 3. Sometimes employed as a synonym for carrier system.
Industry:Telecommunications
A wave that (a) propagates in a transmission medium, (b) has a velocity determined by the launching conditions and the physical properties of the medium, and (c) may be a longitudinal or transverse wave. Note 1: For the purposes of this definition, free space may be considered a medium, although it is not a physical medium. Note 2: A traveling wave is not a wave that is reduced to a standing wave by reflections from a distant boundary. Note 3: Examples of traveling waves are radio waves propagating in free space, lightwaves propagating in optical fibers, water waves on the surface of the ocean, and seismic waves.
Industry:Telecommunications
A wave that has been reflected by a discontinuity in the propagation medium. 2. A wave that has been reflected or otherwise returned with sufficient magnitude and delay to be perceived. Note 1: Echoes are frequently measured in dB relative to the directly transmitted wave. Note 2: Echoes may be desirable (as in radar) or undesirable (as in telephone systems. ) 3. In computing, to print or display characters (a) as they are entered from an input device, (b) as instructions are executed, or (c) as retransmitted characters received from a remote terminal. 4. In computer graphics, the immediate notification of the current values provided by an input device to the operator at the display console.
Industry:Telecommunications
A wave that has two significant conditions, i.e., two levels of amplitude, that change from one condition to the other in a relatively short time compared to the wavelength. Note: When the instantaneous amplitude is plotted versus time or distance, the waveform has a rectangular shape.
Industry:Telecommunications
A wave that is guided along the interface between two different media or by a refractive index gradient. Note 1: The field components of the wave diminish with distance from the interface. Note 2: Optical energy is not converted from the surface wave field to another form of energy and the wave does not have a component directed normal to the interface surface. Note 3: In optical fiber transmission, evanescent waves are surface waves. Note 4: In radio transmission, ground waves are surface waves that propagate close to the surface of the Earth, the Earth having one refractive index and the atmosphere another, thus constituting an interface surface.
Industry:Telecommunications
A wave whose surfaces of constant phase are infinite parallel planes normal to the direction of propagation. 2. An electromagnetic wave that predominates in the far-field region of an antenna, and has a wavefront that is essentially in a plane. Note: In free space, the characteristic impedance of a plane wave is 377.
Industry:Telecommunications
A wave, such as a radio wave or sound wave, that arrives at a given point by reflection or scattering from surrounding objects, rather than directly from the source.
Industry:Telecommunications
A waveguide component having four or more ports, and so arranged that if all ports except one are terminated in the correct impedance, there will be no reflection of energy from the junction when the fourth port is driven by a transmission line having a matching impedance.
Industry:Telecommunications
A waveguide or transmission line arranged such that (a) there are four ports, (b) each port is terminated in its characteristic impedance, and (c) energy entering any one port is transferred, usually equally, to two of the three remaining ports. Note: Hybrid junctions are used as mixing or dividing devices.
Industry:Telecommunications
