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. The antenna intercepts radio waves and converts them to tiny alternating currents which are applied to the receiver, which extracts the desired information. The receiver uses electronic filters to separate the wanted radio frequency signal from all other signals, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation and decoding. The information produced by the receiver may be in the form of sound (an audio signal), images (a video signal) or data (a digital signal). A radio receiver may be a separate piece of electronic equipment, or an electronic circuit within another device. Devices that contain radio receivers include television sets, FM radios, radar equipment, cell phones, wireless computer networks, GPS navigation devices, satellite dishes, bluetooth enabled devices, garage door openers, and baby monitors.