HOW DOES A RADIO TRANSMITTER WORKS
Transmitter is an electronic device which generates a radio frequency alternating current. Whenever a connected antenna becomes excited by this alternating current the antenna emits radio waves. HOW DOES IT WORKS? Radio transmitter is an electronic circuit which transforms electric power from a battery or electrical mains into a radio frequency alternating current which further reverses direction millions to billions of times per second. There is a lot of energy needed to do this. This energy is a rapidly reversing current which can radiate off a conductor as electomagnetic waves. The transmitter also impresses information such as an audio or video signal into the radio current to be carried by the radio waves. When the waves strike the antenna of a radio reciever the waves excite similar radio frequency currents in it. The radio receiber extracts the information from the received waves. Usually a radio transmitter consists of these parts: A power supply which is used to transform the input electrical power to the higher voltages needed to produce the input electrical power to the higher voltages needed to produce the required power output. An electronic oscillator circuit to generate the radio frequency signal which generates sine wave of constat amplitude often called the carrier wave. It is called carrier wave because it serves to 'carry' the information through space. In most modern transmitters this is a crystal oscillator in which the frequency is precisely controlled by the vibrations of a quartz crystal. lastly, a modulator circuit to add the information to be transmitted to the carrier wave produced by the oscillator. It is done by varying some aspect of the carrier wave. The information is provided to the transmitter either in an audio signal form which reperesents soun or a video signal or for data in the form of a binary digital signal. There are many other modulation which are used. The oscillator an dmodulator in large transmitters together are often referred to as the exciter. CONCLUSION Radio transmitters are also used in broadcasting, necessary componenet parts of mny electronic devices that communicate by radio. For example cell phones, garage door openers, two-way radios in air crafts and ships etc.