When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Radiation-absorbent material - Wikipedia

    en.wikipedia.org/wiki/Radiation-absorbent_material

    With each bounce, the wave loses energy to the foam material and thus exits with lower signal strength. [1] An alternative type of RAM comprises flat plates of ferrite material, in the form of flat tiles fixed to all interior surfaces of the chamber. This type has a smaller effective frequency range than the pyramidal RAM and is designed to be ...

  3. Absorption (electromagnetic radiation) - Wikipedia

    en.wikipedia.org/wiki/Absorption_(electromagnetic...

    In physics, the D-region of Earth's ionosphere is known to significantly absorb radio signals that fall within the high-frequency electromagnetic spectrum. In nuclear physics, absorption of nuclear radiations can be used for measuring the fluid levels, densitometry or thickness measurements. [2]

  4. Ionospheric absorption - Wikipedia

    en.wikipedia.org/wiki/Ionospheric_absorption

    The ionosphere can be described as an area of the atmosphere in which radio waves on shortwave bands are refracted or reflected back to Earth. As a result of this reflection, which is often key in the long-distance propagation of radio waves, some of the shortwave signal strength is decreased.

  5. Earth–ionosphere waveguide - Wikipedia

    en.wikipedia.org/wiki/Earth–ionosphere_waveguide

    The Earth–ionosphere waveguide [1] is the phenomenon in which certain radio waves can propagate in the space between the ground and the boundary of the ionosphere. Because the ionosphere contains charged particles, it can behave as a conductor. The earth operates as a ground plane, and the resulting cavity behaves as a large waveguide.

  6. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    Earth's atmosphere is mainly transparent to radio waves, except for layers of charged particles in the ionosphere which can reflect certain frequencies. Radio waves are extremely widely used to transmit information across distances in radio communication systems such as radio broadcasting, television, two way radios, mobile phones ...

  7. An unusual object has been releasing pulses of radio waves in ...

    www.aol.com/news/unusual-object-releasing-pulses...

    “The object we’ve discovered is spinning way too slowly to produce radio waves — it’s below the death line,” Hurley-Walker said. “Assuming it’s a magnetar, it shouldn’t be possible ...

  8. Kennelly–Heaviside layer - Wikipedia

    en.wikipedia.org/wiki/Kennelly–Heaviside_layer

    It reflects medium-frequency radio waves. Because of this reflective layer, radio waves radiated into the sky can return to Earth beyond the horizon. This "skywave" or "skip" propagation technique has been used since the 1920s for radio communication at long distances, up to transcontinental distances. Propagation is affected by the time of day.

  9. A mysterious source has been sending radio signals to Earth ...

    www.aol.com/news/mysterious-source-sending-radio...

    For premium support please call: 800-290-4726 more ways to reach us