In radio communications, a radio receiver is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna.
Alexander Stepanovich Popov designed and implemented the first radio receiver in 1896. It was based on electromagnetic waves, which were proven to exist by James Clerk Maxwell only a few years earlier in 1887.
The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna. Radio receivers are essential components of all systems that use radio. The information produced by the receiver may be in the form of sound, moving images (television), or digital data.
A radio receiver may be a separate piece of electronic equipment, or an electronic circuit within another device. The most familiar type of radio receiver for most people is a broadcast radio receiver, which reproduces sound transmitted by radio broadcasting stations. A broadcast receiver is commonly called a "radio". However radio receivers are very widely used in other areas of modern technology, in televisions, cell phones, wireless modems and other components of communications, remote control, and wireless networking systems.
The radio requires electric power, provided by batteries inside the radio. All radios have a volume control to adjust the loudness of the audio, and some type of "tuning" control to select the radio station to be received.
The receiver is still undergoing many technological advances, especially with the recent increase in the use of digital signals. These digital signals have paved the way for new technologies such as satellite radio and digital TV (DTV).