A radio antenna (or just aerial) is a transducer that can send and receive radio waves (electromagnetic waves) designed for radio, TV, cell phones, radar or satellite. A radio antenna is a transducer with a usable efficiency can perform one or both of these energy conversions: marketable alternating electrical energy for transmission of radio wave energy. Marketable radio wave energy to alternating electrical energy (military antennas).
This parameter is defined as the ratio between the maximum radiated power in a geometric direction and power radiated in opposite direction. When this relationship is reflected in dB scale, the ratio F / B (Front / Back) is the difference in dB between the maximum radiation level and radiation level of 180 degrees. This parameter is especially useful when interference back is critical in choosing the antenna that we use.
A typical loop antenna is made of copper, in resonance with a variable capacitor when transmitting and can withstand high voltages. The transmission can take many amps and the voltage across the capacitor several kilovolts. Loops of copper are more effective than lower managers, due to the large flow. Loops are circular and more efficient than squares, an alternative is octagoner that are easier to manufacture.
Loops are only effective at resonance, and must therefore be geared to operate, high q, very narrow bandwidth. All within about 10 wavelengths (near field) of an antenna may affect its radiation patterns. An antenna is the most "sensitive" in its main cones, there where it has "gain" in a free field radiation pattern.
If the antenna is replaced by the radiation resistance, this would do their job, ie, would produce the same amount of power that the antenna would radiate. The radiation resistance is equal to the ratio of the power radiated by the aerial divided by the square of the current in its feed point. One could obtain an mast efficiency, given that is the ratio of the radiated power and the dissipated power.
There are three basic types of transmitters: wire, aperture and planar antennas. Also, clusters of these aerials (arrays) are usually considered in the literature as another basic type of antenna. Wire transmitters are variants whose radiating elements are wire conductors having a negligible section relative to wavelength employment.
The polarization can be linear, circular and elliptical. Linear polarization can take different orientations (horizontal, vertical, +45, -45). The circular or elliptical polarizations can be right or left (right-handed or left-handed), according to the direction of rotation of the field (observed away from the antenna). Transmitters within decoupling coefficient defined polarization. This measures the amount of power that is capable of receiving a polarized antenna of a form having an effective.
The characteristics of an antenna depends on the relationship between the dimensions and the wavelength of a signal transmitted or received radio frequency. If the masts dimensions are much smaller than the wavelength are called elementary antennas, whether they have dimensions of order of a half wavelength resonating and if its size is much larger than the wavelength are directives.
This parameter is defined as the ratio between the maximum radiated power in a geometric direction and power radiated in opposite direction. When this relationship is reflected in dB scale, the ratio F / B (Front / Back) is the difference in dB between the maximum radiation level and radiation level of 180 degrees. This parameter is especially useful when interference back is critical in choosing the antenna that we use.
A typical loop antenna is made of copper, in resonance with a variable capacitor when transmitting and can withstand high voltages. The transmission can take many amps and the voltage across the capacitor several kilovolts. Loops of copper are more effective than lower managers, due to the large flow. Loops are circular and more efficient than squares, an alternative is octagoner that are easier to manufacture.
Loops are only effective at resonance, and must therefore be geared to operate, high q, very narrow bandwidth. All within about 10 wavelengths (near field) of an antenna may affect its radiation patterns. An antenna is the most "sensitive" in its main cones, there where it has "gain" in a free field radiation pattern.
If the antenna is replaced by the radiation resistance, this would do their job, ie, would produce the same amount of power that the antenna would radiate. The radiation resistance is equal to the ratio of the power radiated by the aerial divided by the square of the current in its feed point. One could obtain an mast efficiency, given that is the ratio of the radiated power and the dissipated power.
There are three basic types of transmitters: wire, aperture and planar antennas. Also, clusters of these aerials (arrays) are usually considered in the literature as another basic type of antenna. Wire transmitters are variants whose radiating elements are wire conductors having a negligible section relative to wavelength employment.
The polarization can be linear, circular and elliptical. Linear polarization can take different orientations (horizontal, vertical, +45, -45). The circular or elliptical polarizations can be right or left (right-handed or left-handed), according to the direction of rotation of the field (observed away from the antenna). Transmitters within decoupling coefficient defined polarization. This measures the amount of power that is capable of receiving a polarized antenna of a form having an effective.
The characteristics of an antenna depends on the relationship between the dimensions and the wavelength of a signal transmitted or received radio frequency. If the masts dimensions are much smaller than the wavelength are called elementary antennas, whether they have dimensions of order of a half wavelength resonating and if its size is much larger than the wavelength are directives.
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