free-space propagation

free-space propagation

[′frē ‚spās ‚präp·ə′gā·shən]
(electromagnetism)
Propagation of electromagnetic radiation over a straight-line path in a vacuum or ideal atmosphere, sufficiently removed from all objects that affect the wave in any way.
References in periodicals archive ?
The test network has 90 nodes, all of which follow random direction mobility model and free-space propagation model.
s)] were consistently different in the near zone but the same in the mid zone, without any indication how the degree of polarization could change during the free-space propagation of light.
As shown in Figure 1, the free-space propagation (also sometimes called line-of-sight) model is appropriate for propagation in which there are no significant reflection paths.
The results shown assume isotropic transmit and receive antennas, and free-space propagation conditions (path loss exponent = 2).
This makes it possible to simulate free-space propagation and avoid parasitic reflections,which result in dramatically improved precision when measuring the electromagnetic spectrum below 1GHz.
P] (dB) is free-space propagation path loss, F (MHz) is frequency and D (meters) is propagation path length.
To test antijamming utilities suggests the need to generate a jamming signal, but if not strictly controlled, free-space propagation of such jamming could cause chaos in the civilian sector.
The various phenomena described include free-space propagation above regular and irregular terrain, reflection and diffraction by various obstacles regularly or randomly distributed on the terrain, and effects of scattering from such obstructions and from the ground surface.
The module includes an enhanced free-space propagation model, as well as a comprehensive range of capabilities for modeling customer premise equipment (CPE), ensuring optimal transmitter placement, planning capacity and reusing spectrum aggressively.
This attenuation rate is in contrast to the 6 dB per octave of distance associated with free-space propagation.
Antennas are reciprocal devices that couple electromagnetic energy to (or from) the guided-wave mode of a transmission line to free-space propagation.
For free-space propagation, v = 2, but v increases with increasing multipath components and obstructions.