Work out link budget instantly with clear inputs, formula shown and shareable results.
A link budget adds gains and subtracts losses in decibels: received power equals transmit power plus antenna gains minus path and cable loss. Subtracting receiver sensitivity gives the fade margin, and 10-20 dB is normally required to ride out rain, multipath and seasonal foliage.
Link budget
Prx = Ptx + Gtx + Grx - path loss - cable loss; margin = Prx - sensitivity
10 dB for a short indoor link, 15-20 dB for an outdoor link, and more at frequencies above 10 GHz where rain fade is severe.
It is a power referenced to 1 mW, and receivers work with picowatts, so the dBm figure is a large negative number.