https://blogs.keysight.com/content/usergenerated/asi/cloud/attachments/keysight-blog/en/blogs/tech/bench/jcr%3Acontent/root/responsivegrid/keysight_layout_cont_526586764/colcntrl-1/column-1/journal/how_to_couple_thefr-pihI/images/scope_frequencyoffset.png