This converter calculates the free space path loss (FSPL) of an RF signal between a transmitting antenna and a receiving antenna. FSPL quantifies signal attenuation as a function of distance and frequency, while accounting for antenna gains.
Formula
FSPL(dB) = 20 × log 10 (d) + 20 × log 10 (f) + 92.45 – G Tx – G Rx
Explanation of the formula
The formula uses the distance between the antennas (d, in km) and the signal frequency (f, in GHz). We apply 20 log10 to each parameter to convert the ratios into decibels. The term 92.45 corresponds to the conversion constant of units and the speed of light in free space. The antenna gains G Tx and G Rx are then subtracted to obtain the net loss.
Uses
- Evaluate the expected attenuation of an RF signal in free transmission, without obstacles.
- Design and dimension radio links or wireless networks over long distances.
- Compare different antenna configurations and frequencies to optimize coverage.
- Predict the power required to achieve reliable reception in communications systems.