Information can be sent from a transmitter to a receiver by means of modulation and demodulation, respectively, whether those signals are light waves moving through optical cables, radio waves through metallic cables, or radio waves propagating through the air. The electromagnetic (EM) waves that transport the information are referred to as carrier signals, while the information they carry may be in the form of audio, video, or data...
Register or Sign in below to download the full article in .PDF format, including high-resolution graphics and schematics when applicable.