rádiójel

A rádiójel is a form of electromagnetic radiation used for transmitting information wirelessly. It falls within the radio frequency portion of the electromagnetic spectrum, typically ranging from about 3 kilohertz to 300 gigahertz. Radio waves are generated by oscillating electric charges, such as those in an antenna.

These waves travel at the speed of light and can propagate through a vacuum, such as space, as well as through the Earth's atmosphere. The properties of radio waves, such as their frequency and wavelength, determine their behavior and how they are used. Higher frequencies generally travel in straighter lines and are more easily blocked by obstacles, while lower frequencies can diffract around objects and bounce off the ionosphere, allowing for longer-distance communication.

Radio signals are fundamental to many modern technologies. They are employed in broadcasting for radio and television, in telecommunications for mobile phones and Wi-Fi, in radar systems for detecting objects, and in navigation systems like GPS. The modulation of a carrier radio wave with information, such as audio or data, allows for the transmission of specific content. The reception of these signals is achieved using a radio receiver, which is typically tuned to a specific frequency. The interpretation and decoding of the modulated signal then reconstruct the original information.