Hi everyone, can you tell me please my calculations are correct?
1. 15 dBm differential sine waves at external 100 Ohm resistor is equivalent to -12 dBm total power at differential input.
2. 12 dBm at external 100 Ohm resistor is ~0.22 V peak to peak (i.e. 0.39 to 0.61 V (with 0.5 V DC bias) in each single line).
3. 0.22 V =-13 dBV (100 Ohm)
4. -13 dBV + (10~13)dB VGain=-2~0.9 dBm (100 Ohm)
ad 1/ I think you mean -15dBm (not +15dBm). Yes, you are right, combined power is -12dBm (impedances shall be matched, but exact value is not important)
ad 2/ Yes, -12dBm corresponds 0.22Vpp at 100Ohm
ad 3/ Yes, in case of peak-peak
ad 4/ I think -2dBVpp corresponds to -1dBm for Z=100Ohm
Thank you, Viktor