No he thought it up himself.When you say he "popularized" the idea you make it sound like it was borne of his fiction writings.Dont get me wrong Im sure theres plenty of credit to go around for the invention and implementation.But lets give the man his credit for the concept.
http://lakdiva.org/clarke/1945ww/
I'm must apologise for saying this if it offends. Whatever the questionable merits of his writing as art, I have to take issue with the various claims (especially his own)about all the stuff he "invented" or "had the idea for".
Does anyone truly believe, that, the process for the development of the communication satellite owes itself somehow to his idea? If indeed he did have it first, which is something I have heard many times, is in fact a dubious claim at best.
He wrote science fiction remember, and of all the millions of ideas, life styles, gadgets etc. made up in the genre, isn't it more likely that eventually a couple of them might come to fruition, just based on the odds? Or that someone somewhere was already working on it, and he heard about it? In fact this is exactly what happened and the original idea came from Hermann Oberth, a german scientist in 1923! He proposed reflective mirrors rather than radio waves. Optical linking has only just occured in Communication satellites by the way, but the principle is the same as using radio waves. Edward Everett Hale even suggest an artificial moon could be used for navigation long before that in the 1830's. George O. Smith had space relay stations in orbit around the earth and in space prior to Clarke in a his book Venus Equilateral printed in 1943...Clarke himself admits his "idea" came from discussions with friends who all worked in Radar.
I must ask, are the writers of the Jetsons responsible for private aircraft? Then we have L. Ron Hubbard. When it comes to inventing stuff, I think he wins the gold, don't you?
It's all nonsense and just the sound of a giant ego exercising.
Science fiction of ACC's type is better than not reading at all, but we must be careful when we label people "a visionary", it usually is not that simple. As a modest Newton once said, "If I have seen further, it is because I have stood on the shoulders of giants." . You want visionary, read Orwell or Huxley, even Frank Herbert!
It's recognizing that they made some very important contributions in one area but were a very damaging person to people in other parts of their lives. It's not so black and white as "he had sex with boys so that means everything he did as a writer is now completely null and void". 
