Queries about AD10200

Dear Supporter,

I used AD10200 in my project. I tested AD10200 with signal generator. The sampling clock is 105MHz. FFT N=65536.

When I input 10MHz sine wave, the FFT result looks good. Please see below pic.

but when I input 41MHz, 71MHz or 105MHz respectively, the results look poor, please see below pics.

I am not sure why the waves are abnormal. Could you please help give me some comments on the issues?

Thanks in advance for your help!

Br,

Wayne