Carrier wave
At the sending end, the information, in the form of a modulation signal, is applied to an electronic device called a transmitter.In the transmitter, an electronic oscillator generates a sinusoidal alternating current of radio frequency; this is the carrier wave.The alternating current is amplified and applied to the transmitter's antenna, radiating radio waves that carry the information to the receiver's location.Carriers are also widely used to transmit multiple information channels through a single cable or other communication medium using the technique of frequency division multiplexing (FDM).The information in a modulated radio signal is contained in the sidebands while the power in the carrier frequency component does not transmit information itself, so newer forms of radio communication (such as spread spectrum and ultra-wideband), and OFDM which is widely used in Wi-Fi networks, digital television, and digital audio broadcasting (DAB) do not use a conventional sinusoidal carrier wave.
frequency spectrumsidebandsbandwidthtelecommunicationswaveformsinusoidalmodulationfrequencyelectromagnetic waveradio communicationfrequency division multiplexingcable televisionemissionmusic productionradio wavestransmitterelectronic oscillatoralternating currentradio frequencymodulatereceiverdemodulationfrequency modulationamplitude modulationspectrumsingle-sideband modulationbeat frequency oscillatorcommunication mediumcoaxial cablebandpass filterstuned circuitswavelength division multiplexingoptical fiberspread spectrumultra-widebanddigital televisiondigital audio broadcastingcrosstalkfrequency mixersCarrier recoveryCarrier systemCarrier toneFrequency-division multiplexingSidebandFederal Standard 1037CMIL-STD-188HistoryBroadcastingCable protection systemCable TVData compressionDigital mediaInternet videoonline video platformsocial mediastreamingEdholm's lawInformation AgeInformation revolutionInternetMobile phoneSmartphoneOptical telecommunicationOptical telegraphyPhotophonePrepaid mobile phoneRadiotelephoneSatellite communicationsSemaphorePhryctoriaSemiconductordeviceMOSFETtransistorSmoke signalsTelecommunications historyTelautographTelegraphyTeleprinterTelephoneThe Telephone CasesTelevisiondigitalVideotelephonyWhistled languageWireless revolutionNasir AhmedEdwin Howard ArmstrongMohamed M. AtallaJohn Logie BairdPaul BaranJohn BardeenAlexander Graham BellEmile BerlinerTim Berners-LeeFrancis BlakeJagadish Chandra BoseCharles BourseulWalter Houser BrattainVint CerfClaude ChappeYogen DalalDaniel Davis Jr.Donald DaviesAmos DolbearThomas EdisonLee de ForestPhilo FarnsworthReginald FessendenElisha GrayOliver HeavisideRobert HookeErna Schneider HooverHarold HopkinsGardiner Greene HubbardInternet pioneersBob KahnDawon KahngCharles K. KaoNarinder Singh KapanyHedy LamarrRoberto Landell de MouraInnocenzo ManzettiGuglielmo MarconiRobert MetcalfeAntonio Meucci