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  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. Corner reflector - Wikipedia

    en.wikipedia.org/wiki/Corner_reflector

    These reflect radio waves coming from in front of them back parallel to the incoming beam. To create a corner reflector that will reflect radar waves coming from any direction, 8 corner reflectors are placed back-to-back in an octahedron (diamond) shape. The reflecting surfaces must be larger than several wavelengths of the radio waves to ...

  5. Reflector (antenna) - Wikipedia

    en.wikipedia.org/wiki/Reflector_(antenna)

    The function of a standalone reflector is to redirect electromagnetic (EM) energy, generally in the radio wavelength range of the electromagnetic spectrum. Common standalone reflector types are corner reflector, which reflects the incoming signal back to the direction from which it came, commonly used in radar.

  6. Radio wave - Wikipedia

    en.wikipedia.org/wiki/Radio_wave

    VLF and ELF radio waves can also penetrate water to hundreds of meters deep, so they are used to communicate with submerged submarines. Skywaves: At medium wave and shortwave wavelengths, radio waves reflect off conductive layers of charged particles in a part of the atmosphere called the ionosphere. So radio waves directed at an angle into the ...

  7. Ground plane - Wikipedia

    en.wikipedia.org/wiki/Ground_plane

    For a monopole antenna (a), the Earth acts as a ground plane to reflect radio waves directed downwards, making them seem to come from a virtual "image antenna" (b).In Telecommunications, a ground plane is a flat or nearly flat horizontal conducting surface that serves as part of an antenna, to reflect the radio waves from the other antenna elements.

  8. Electromagnetic radiation - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_radiation

    EMR of lower energy ultraviolet or lower frequencies (i.e., near ultraviolet, visible light, infrared, microwaves, and radio waves) is non-ionizing because its photons do not individually have enough energy to ionize atoms or molecules or to break chemical bonds. The effect of non-ionizing radiation on chemical systems and living tissue is ...

  9. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    Radio waves, at the low-frequency end of the spectrum, have the lowest photon energy and the longest wavelengths—thousands of kilometers, or more. They can be emitted and received by antennas , and pass through the atmosphere, foliage, and most building materials.