The antenna factor equation in a 50-ohm system is expressed as:
$$AF={9.73 \over \lambda*\sqrt(Gain)}$$
Where Gain is in dB, the wavelength in meter and the calculated AF is in dB/m. $$$$ First, How the unit of the calculated AF is in dB/m? $$$$
Second, there is also another shape of the antenna factor formula where:
$$AF={20*log({9.73 \over \lambda*\sqrt(Gain)})}$$
Where Gain is in numeric form and the AF is in dB/m.
May I ask for some help about deriving this equation? $$$$
In case of a negative gain (in dB), I converted it to a numeric form knowing:
$$Gain (dB)={10*log(Gain(num))}$$
$$$$
and then used the second formula. Is it ok to do so?
$$$$
Last, How it is possible to convert dB/m to 1/m.
Is it Ok to use this general formula?
$$AF(db/m)={10*logAF(1/m)}?$$
Thanks.