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LEARN 

about radio

These modules will lead educators through key concepts in the science, engineering and social impacts of radio frequency technologies. 

 

It explores the pervasiveness of radio and its role in modern communication, highlighting how engineers use electromagnetic waves to transmit information and the challenges of a limited radio spectrum. It also examines the societal impact and future potential of radio, emphasizing the need for equitable technology development through collaborative efforts.

  • What is radio?

    Radio is everywhere. It is invisible energy carrying data between cell phones and information from Earth to orbiting satellites. Radio waves are also emitted by our planet, objects in outer space, and events like starting a car or turning on a light.

    Radio is a field of scientific and technological research making significant changes in how we communicate, work and live. Wireless connectivity plays a starring role in history and our future, encompassing everyday communication, healthcare and remote monitoring systems.

    When the first radio communication was used to send a message across great distances using wireless telegraphy in 1895, the airspace was changed forever. Today, radio waves are used by wireless laptops, remote-control car locks, AirPods and Internet-of-Things devices. Radio is employed for air traffic control, spacecraft communications and astronomical research.

    Radio frequency technologies continue to be developed through innovations in science and engineering. Equally important for society are the policies governing radio usage by everyone.

    Like many innovative technologies on the horizon, it is vital that everyone is informed about radio and has a voice in how it shapes our future. We each have a role to play. Our decisions about how to use and share the radio spectrum shape our individual lives, society and the world.

  • Every electrical device, including the wires and appliances in your home, generates an electromagnetic field.

    Our eyes can perceive visible light, a type of electromagnetic (EM) radiation, but they are incapable of detecting other forms of the EM spectrum, including radio waves.

    AM/FM Radios are designed to receive specific frequencies of EM radiation and convert this energy into sound.

    Microwave ovens use EM radiation to transfer energy directly to water molecules, thereby heating up food.

    Sunglasses and sunscreen block or filter specific kinds of EM radiation, like ultraviolet (UV) light.

    Computers and cell phones transmit and receive information using technologies that function within the radio frequency spectrum.

    X Ray machines use high-energy "ionizing" EM radiation, which is different from the low-energy "non-ionizing" radiation found in radio waves and light. 

    Astronomical telescopes capture EM radiation emitted by interstellar objects, such as quasars and nebulas. Almost all astronomical events generate radio waves. 

    Electromagnetic radiation is around us at all times

    Radio is a form of electromagnetic (EM) radiation. Light and energy from the sun are also EM radiation, as are infrared light and microwaves. 

    Electromagnetic radiation in everyday life

    Every electrical device,

    including the wires and appliances in your home, generates an electromagnetic field.

    Our eyes

    can perceive visible light, a type of electromagnetic (EM) radiation, but they are incapable of detecting other forms of the EM spectrum, including radio waves.

    AM/FM Radios

    are designed to receive specific frequencies of EM radiation and convert this energy into sound.

    Microwave Ovens

    use EM radiation to transfer energy directly to water molecules, thereby heating up food.

    Sunglasses & Sunscreen

    block or filter specific kinds of EM radiation, like ultraviolet (UV) light.

    Computers and Cell Phones

    transmit and receive information using technologies that function within the radio frequency spectrum.

    X-Ray Machines

    use high-energy "ionizing" EM radiation, which is different from the low-energy "non-ionizing" radiation found in radio waves and light.

    Astronomical Telescopes

    capture EM radiation emitted by interstellar objects, such as quasars and nebulas. Almost all astronomical events generate radio waves.

  • Radio waves are different lengths

    Electromagnetic (EM) radiation travels in the form of a wave, classified by each wave's length – or wavelength. Radio waves vary in wavelength, ranging from as small as a millimeter to as long as a hundred kilometers – about 62 miles! These varying wavelengths make up the "radio spectrum," which is a segment of the broader EM radiation range characterized by the longest wavelengths. 

    Sections, or "bands," of the spectrum are defined by their range of wavelengths. Another common method to describe radio wave lengths is through their frequency—the number of waves that form in one second. Frequency can be measured in hertz (Hz), megahertz (MHz) and gigahertz (GHz). One Hz equals one cycle per second, while one GHz equals one billion cycles per second. 

    The radio band, characterized by its long wavelengths, is highlighted within the full EM spectrum. The portion depicted as a rainbow represents the band of visible light that is detectable by our eyes."

    AM Radio

    The EM wave transmitted by AM Radio stations can be as long as a city block (580 ft to 1,820 ft).

    Wi-Fi

    A 5GHz WiFi router transmits EM waves about as long as the bee hummingbird, the world's smallest bird (6cm).

    5G

    Millimeter waves, found within the bands used for 5G communications, can have wavelengths about as long as a grain of rice, roughly 7.7mm.

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