Where
λ = Wavelength in feet
v = Velocity of propagation in feet per second
f = Frequency in Hz
f = 1 / T
Where
f = Frequency in Hz
T = Time of one wave period (cycle) in second
Path Loss and Vertical Dipole Isolation
Path Loss (dB) = 10log (λ/4πr)^{2}
Isolation (dB) = 28 + 40log (h/λ)
Where
λ = Wavelength in metres
r = Distance between transmitting and receiving antennas in metres
h = Vertical antenna separation
VSWR, Reflection Coefficient (ρ) and Return Loss
VSWR = (1 + ρ)/(1 - ρ)
ρ = (VSWR - 1)/(VSWR + 1)
Return Loss (dB) = -20logρ
Power Received by an Antenna
P = P_{t}G_{t}G_{r}λ^{2} / 16π^{2}d^{2}
Where
P = Power received in Watts
P_{t} = Power transmitted in Watts
G_{t} = Gain ratio of transmitting antenna relative to an isotropic radiator
G_{r} = Gain ratio of receiving antenna relative to an isotropic radiator
λ = Wavelength in metres
d = Distance between transmitting and receiving antennas in metres
Effective Radiated Power
ERP = G x P
Where
G = Gain of transmitting antenna relative to an isotropic radiator
P = Input Power in Watts
VSWR Vs Return Loss and Effect of VSWR on Transmitted Power