Path Loss Equations

Standard "Friis" equation for free space loss between isotropic radiators:

Loss dB = 32.44 + 20 log (dist in km) + 20 log (freq in MHz)

13.402 GHz, 1000 km => 175 dB

radio/pathloss.htm - 22 Jan 2003 - Jim Lux
(radio) (Jim's home page)