Frecuency response

Hi, I'm try to plot the frecuency response of a paralell R-C circuit when it exciting for a train pulse signal. I do this: -pulse signal is generated by pulse generator in simulink -i join this signal with the SimRFInport -then folows the RC paralell -the RC is joined to SimRF Outport -finishing i join SimRf Outport to a Scope (i add a solver configuration to the model)

I need to watch the frecuency response of the circuit but it don't work. The signal at scope port must be double and the signal of simRF outport is complex.

What can i do to resolve this problem? can i do the model in a different way, may be using simscape?

Any help is appreciate. Thanks in advance. Néstor.