Free space path loss
Calculate Free-Space Path Loss
Calculate the free-space path loss (in dB) of a 10 GHz radar signal over a distance of 10 km.
fc = 10.0e9; lambda = physconst('LightSpeed')/fc; R = 10e3; L = fspl(R,lambda)
L = 132.4478
R — Propagation distance of signal
real-valued 1-by-M or M-by-1
Units are in meters.
lambda — Speed of propagation divided by the signal frequency
real-valued 1-by-N or N-by-1
Wavelength units are meters.
Free Space Path Loss
The free-space path loss, L, in decibels is:
This formula assumes that the target is in the far-field of the transmitting element or array. In the near-field, the free-space path loss formula is not valid and can result in a loss smaller than 0 dB, equivalent to a signal gain. For this reason, the loss is set to 0 dB for range values R ≤ λ/4π.
 Proakis, J. Digital Communications. New York: McGraw-Hill, 2001.
C/C++ Code Generation
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Usage notes and limitations:
Does not support variable-size inputs.
Introduced in R2011a