Friis Equation
Friis equation calculates the received power from an antenna at some distance given a transmission frequency and antenna gains.
The subject of the equation can be changed to find the distance R, between two antennas as shown below;
`R= lambda/(4pi) * sqrt((Pr * Gr * Gt ast gamma ast rho)/(Pth)`
where,
- `lambda` = Receiver Efficiency
- `gamma` = Impedance Mismatch Coefficient
- `rho` = Polarization Coefficient
- Pth = Chip Threshold Power
- Pr = Receiver Power
- Gr = Receiver Antenna Gain
- Gt = Transmitter Antenna Gain