Maximum Frequency Matlab/Simulink can simulate?

I have a device I am trying to simulate that operates at 16.7 GHz. I am using simulink and have the output sent to a "Power Spectral Density" node, but when I run the simulation, nothing appears. When I change the frequency to 300 MHz, the simulation runs no problem. Is this an issue with the way I have set up the simulation or is 16.7 GHz simply too high of a frequency for the program to simulate? I have attached an image of the diagram. The function does a convolution of the two signals. If you have any questions just ask. Thanks