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  2. Fresnel zone - Wikipedia

    en.wikipedia.org/wiki/Fresnel_zone

    This means objects which are clear of the line of sight path will still potentially block parts of the signal. To maximize signal strength, one needs to minimize the effect of obstruction loss by removing obstacles from both the direct radio frequency line of sight (RF LoS) line and also the area around it within the primary Fresnel zone. The ...

  3. Radio frequency - Wikipedia

    en.wikipedia.org/wiki/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 ...

  4. Near and far field - Wikipedia

    en.wikipedia.org/wiki/Near_and_far_field

    The near field refers to places nearby the antenna conductors, or inside any polarizable media surrounding it, where the generation and emission of electromagnetic waves can be interfered with while the field lines remain electrically attached to the antenna, hence absorption of radiation in the near field by adjacent conducting objects detectably affects the loading on the signal generator ...

  5. Radio-frequency engineering - Wikipedia

    en.wikipedia.org/wiki/Radio-frequency_engineering

    Radio-frequency (RF) engineering is a subset of electrical engineering involving the application of transmission line, waveguide, antenna, radar, and electromagnetic field principles to the design and application of devices that produce or use signals within the radio band, the frequency range of about 20 kHz up to 300 GHz.

  6. Radio wave - Wikipedia

    en.wikipedia.org/wiki/Radio_wave

    The radio spectrum is divided into a number of radio bands on the basis of frequency, allocated to different uses. Higher-frequency, shorter-wavelength radio waves are called microwaves. Diagram of the electric fields (E) and magnetic fields (H) of radio waves emitted by a monopole radio transmitting antenna (small dark vertical line in the ...

  7. Antenna (radio) - Wikipedia

    en.wikipedia.org/wiki/Antenna_(radio)

    [1] [2] It is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. [1] In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio

  8. Radiation pattern - Wikipedia

    en.wikipedia.org/wiki/Radiation_pattern

    The level of minor lobes is usually expressed as a ratio of the power density in the lobe in question to that of the major lobe. This ratio is often termed the side lobe ratio or side lobe level. Side lobe levels of −20 dB or greater are usually not desirable in many applications.

  9. Fractal antenna - Wikipedia

    en.wikipedia.org/wiki/Fractal_antenna

    A fractal antenna is an antenna that uses a fractal, self-similar design to maximize the effective length, or increase the perimeter (on inside sections or the outer structure), of material that can receive or transmit electromagnetic radiation within a given total surface area or volume.