I'm simulating an FMCW radar in ADS and to control the VCO I use a ramp generator. I tried the ideal case, now I want to add a ripple to my ramp voltage so I can analyze the effect of a ramp voltage with voltage noise. I don't know how to add ripples to a voltage in ADS. I put a voltage noise source in series with my pulse generator but it shows only the noise in the output and not the noise coupled ramp signal. Could someone help me please on this?