My apologies for not being real clear with the question. I kept doing google searches using various search terms, all of which included the phrase "radio frequency" and I kept getting nowhere. Then, I just used the word "radio" and Bingo! started to get information about how radio works which, of course, includes radio frequency. Unfortunately, I had already posted my question before I started getting better search results. Nevertheless, you've done a wonderful job at answering my question!
Just to be clear, I'd like to make sure I understand something, here. After having done some reading, I've learned that "radio frequency" is basically a sine wave, right? So, now, if I'm getting the "transmitter" stuff right, a circuit designed to transmit radio frequency would first of all create a sine wave and then after creating the sine wave, it would amplify it. Is this correct?
And, wow! Now I know what broadband really means! That's really cool. Thanks.