Sort of ...

The Return Loss is 63dBm - 36dBm = 27dB (that's very good!)

Converting to reflection coefficient, Gamma = 10^(-27dB/20) = 0.0447

Then, VSWR = (Gamma + 1)/(Gamma-1) = 1.09 : 1

No volts or watts but, to be honest, Gamma is a voltage ratio ... :-)

Hope that helped,
Darrell ...

"Gudmundur" wrote in message
...
If I know only the power in dbm is there a formula to arrive at
vswr without conversion first to watts or volts?

outbound = +63dbm (2kw)
reflected = +36dbm (4w)

This is a waveguide system with a dummyload connected in
the event the numbers seem improper.

I would like to use the formula when we connect the real antenna.