I have one query. For SSB generation, the bias voltage of dual electrode MZM needs to be set to VPi/2.
I am designing OFDM system in which I am trying to vary the bias of MZM and checking the EVM at the output. But I am not getting the required result.
According to the theory, if VPi = 4volts, and if I am varying my Vdc (Bias voltage) from 0.2 to 4 volts, then initially with the increase in bias the EVM should drop and reaches its lowest value at Vdc =2 volts. Now when Vdc is increased beyond 2volts, then the EVM should increase. This is due to the MZM non linear distortion.
But I am not getting proper results. I have attached my design below. Please look into it.