I have the same situation in my current work environment. However, I did a little research. First, try to find someone, who is knowledgeable in "radio", they can give you a lot of useful information on designing your own antenna.
In my situation, all I needed was a couple of pieces of copper tubing—cut to precision length based on the frequency of the radio station—and some speaker wire. Drilled a couple of holes into the copper tubes and screwed the speaker wire to the tubes. Now I’m able to receive signals from radio station that is 60 miles away.
HTH,