06-10-2012, 03:41 PM
THERMAL FADE MARGIN
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THERMAL FADE MARGIN
Thermal fade margin TFM in db is the difference between the normal received signal RSL at the input of microwave receiver expressed in dbm and the receiver's threshold ( given by the manufacturer) expressed in dbm
TFM = RSL – TH
PATH LOSS
In telecommunication, free-space path loss (FSPL) is the loss in signal strength of an electromagnetic wave that would result from a line-of-sight path through free space (usually air), with no obstacles nearby to cause reflection or diffraction. It does not include factors such as the gain of the antennas used at the transmitter and receiver, nor any loss associated with hardware imperfections
Path loss is usually expressed in dB. In its simplest form, the path loss can be calculated using the formula
where is the path loss in decibels, is the path loss exponent, is the distance between the transmitter and the receiver, usually measured in meters, and is a constant which accounts for system losses.