I also concern about this question. I want to use ENA to obtain the gain and group delay of an circuit composed of a EO modulator and optical dispersion components, but a warning of 'ENA_1: Warning calculating s-parameters: maximum number of iterations reached.' was shown while using scattering data for frequency domain simulation, and the input port of the ENA is empty. I don't kown if time domain simulation shold be done, and have no idea on how to set the time domain simulation to get the right result.
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