radio
Radio (Italian, German, English, French, Spanish: Radio) or radio frequency refers to electromagnetic waves propagating in free space (including air and vacuum), the frequency below 300GHz (lower frequency is less uniform, in a variety of RF specifications, Common there are three: 3KHz ~ 300GHz, 9KHz ~ 300GHz, 10KHz ~ 300GHz). Radio technology is the technology that propagates signals through radio waves. In astronomy, radio waves are called radio waves, referred to as radio. The principle of radio technology is that changes in the current in the conductor will produce radio waves. With this phenomenon, the information can be loaded on the radio wave by modulation. When the radio waves spread through the space to reach the receiver, radio waves caused by changes in the electromagnetic field will produce current in the conductor. Through the demodulation of information from the current changes in the extraction, to achieve the purpose of information transmission. ...