The antenna gain G_R is related to the aperture A according to

Thus the received signal power is

The received power decreases with distance, P_R :: d^-2

The received power decreases with frequency, P_R :: f ^-2

Path Loss in dB:

L_fs= 32.44 + 20 log (f /1 MHz) + 20 log (d / 1 km)

Broadcast planning (CCIR)

Field strength and received power: E₀ = Ö(120 p P_R)

In free space:

JPL's Wireless Communication Reference Website © Jean-Paul M.G. Linnartz, 1993, 1995.