What is Frequency modulation?
[[File:Amfm2.gif|thumb|right|A sound wave, an '''AM''' wave, and an '''FM''' wave compared]] In [[telecommunication]]s and [[signal processing]], '''frequency modulation''' transmits [[information]] over a carrier wave by varying the [[frequency]]. This technique is different from [[amplitude modulation]] which varies the [[amplitude]], but keeps the frequency constant. This kind of modulation is used in [[broadcasting]] and other [[radio]] work. In the context of [[broadcasting]], Frequency [[modulation]] is often shortened to '''FM'''. When transmitting [[analog signal|analogue]] [[sound]], the sound quality of FM signals is better than that of [[amplitude modulation]] (AM) signals. However, FM signals do not travel as far as AM beause they use higher frequencies that do not bounce off the [[Kennelly–Heaviside layer]]. Many radio stations send out both kinds of signals. AM may be used for talk shows, and FM for music. FM broadcasting usually includes a difference signal, which can cause two different [[speaker]]<nowiki/>s at home to create different sounds. This creates [[stereo]] sound. == Other websites == * [http://www.fas.org/man/dod-101/navy/docs/es310/FM.htm Frequency Modulation] == References == [[Category:Radio technology]]