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  2. Line-of-sight propagation - Wikipedia

    en.wikipedia.org/wiki/Line-of-sight_propagation

    Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves can only travel in a direct visual path from the source to the receiver without obstacles. [1] Electromagnetic transmission includes light emissions traveling in a straight line. The rays or waves may be diffracted ...

  3. Radio propagation - Wikipedia

    en.wikipedia.org/wiki/Radio_propagation

    Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. [1]: 26‑1 As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. [2]

  4. Radio spectrum - Wikipedia

    en.wikipedia.org/wiki/Radio_spectrum

    The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particularly in telecommunication. To prevent interference between different users, the generation and transmission of radio ...

  5. Radio frequency - Wikipedia

    en.wikipedia.org/wiki/Radio_frequency

    Radio frequency. Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency [1] range from around 20 kHz to around 300 GHz. This is roughly between the upper limit of audio frequencies and the lower limit of infrared ...

  6. Eye pattern - Wikipedia

    en.wikipedia.org/wiki/Eye_pattern

    Eye pattern of a 1.25 Gbit/s NRZ signal through a lossy channel. As high frequency losses increase the overall shape of the eye gradually degrades into a sinusoid (once higher frequency harmonics of the data has been eliminated, all that remains is the fundamental) and decreases in amplitude.

  7. High-intensity radiated field - Wikipedia

    en.wikipedia.org/wiki/High-intensity_radiated_field

    A high-intensity radiated field (HIRF) is radio-frequency energy of a strength sufficient to adversely affect either a living organism or the performance of a device subjected to it. A microwave oven is an example of this principle put to controlled, safe use. Radio-frequency (RF) energy is non-ionizing electromagnetic radiation – its effects ...

  8. Visible spectrum - Wikipedia

    en.wikipedia.org/wiki/Visible_spectrum

    The visible spectrum is the band of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light (or simply light). The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ...

  9. Near vertical incidence skywave - Wikipedia

    en.wikipedia.org/wiki/Near_Vertical_Incidence...

    Near vertical incidence skywave, or NVIS, is a skywave radio-wave propagation path that provides usable signals in the medium distances range — usually 0–650 km (0–400 miles). It is used for military and paramilitary communications, broadcasting, [1] especially in the tropics, and by radio amateurs for nearby contacts circumventing line ...