A career in politics wasn't even 'on my radar (screen)' at that point. [=I wasn't thinking at all about a career in politics]
an actor who has 'fallen off the radar' [=who has stopped being noticed or talked about]
He tried to stay 'under the radar' [='unnoticed'] as he went about his business.
(..) write that down for me. And Dr Cox. We've really connected. I'm kind of like his prot'g'. - l need to see his chart... - Done, copied and highlighted. Unfortunately, radar, l'm fresh out of gold stars. Multilobar pneumonia at . How much does he smoke? l don't know. lt's your attention to detail (..)2001 TvShow: Scrubs Title: My Mentor Season: 1 Episode 2