CST Studio Suite ​​​​​​​

Hi, experts,

I have a question about the combine results. I found the meaning in help content: "Assuming your model contains a CST Microwave Studio block or a CST Microwave Studio file block referencing a CST Microwave Studio® project where at least one field monitor (in frequency domain) is defined, CST Design Studio™ allows you to calculate combined fields, driven by the attached circuit." 

That's what combine results is, but when I try to simulate two senarios, one is in 3D MWS with default Port 1 excitation, another is in Schematic with 10v AC excitation, there seems no big difference between them. What the reason?

Thanks.