Convert SWR to reflection coefficient, return loss, mismatch loss and the percentage of power reflected and transmitted.
From the standing wave ratio: reflection coefficient = (SWR - 1) / (SWR + 1). Return loss = -20 log of that, mismatch loss = -10 log of (1 minus coefficient squared), and the fraction of power reflected is the coefficient squared. An SWR of 2:1 reflects only 11 percent of the power, a 0.5 dB loss.
The standing wave ratio measures how well an antenna or load is matched to the feedline. 1:1 is perfect; higher numbers mean more power is reflected back instead of radiated. The reflection coefficient is (SWR - 1) / (SWR + 1).
Not really. A 2:1 SWR reflects about 11 percent of the power and adds only about 0.5 dB of mismatch loss, which is barely noticeable. Most rigs run happily up to 2:1; above that the transmitter may fold back its power.
Return loss is how far down the reflected signal is, in dB. Mismatch loss is how much of your forward power is actually lost because of the reflection. A high return loss (good match) means a very low mismatch loss.