Basic Low Pass Filters in Simulink

Hello all,

I'm struggling to get a very simple filter working in my Simulink simulation. TO put it simply, I have a 100MHz sine wave with a DC offset, with points separated by 1ps (1*10^-12). I am trying to simply filter out as much of the sine wave as I can, pulling out just the offset. While I thought this would be easy, no matter what I try I always end up with a non-negligible sine wave at 100MHz. That is, if I start with an amplitude of say, 0.5 peak to peak, I'm cant get it lower than 0.2 peak to peak, which is unacceptable.

So, I'm not sure what I'm doing wrong. I've tried increasing my order, changing my input Fs, etc, but haven't had any luck.

I imagine I should have my sampling frequency at least double the frequency of 100MHz (Fs>200MHz), but haven't had any luck with that.

If anyone could help my design this filter, I would be very grateful, I've been stuck on this problem for (literally) weeks. Any advice in general is welcome.

Thanks!