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.
Bandwidth is a frequency range in which the antenna parameters meet certain characteristics. Can define impedance bandwidth, polarization, gain or other parameters. Directivity is the impedance of masts at its terminals. It is the relationship between the voltage and the input current. Z = frac V I. The impedance is a complex number. The real part of an impedance is called mast resistance and the imaginary part is reactance.
A transmitter with more than about 3 items are usually less sensitive in a circle slice perpendicular towards the main direction of a jet and therefore one can put antennas in close proximity to a base station. The distance between the antennas should be at least 1 / 2-1 of main wavelengths used. Further away than about 10 wavelengths (far field) affects largely the antenna radiation pattern, but it can affect radio propagation or radio broadcast.
You can also define the beam width between zero, which is the angular range of the main beam of a radiation pattern between two adjacent zeros to maximum. Create antennas radiated electromagnetic fields. Polarized electromagnetic defined in a certain direction, as the geometric shape that traces the edge of electric field vector at a certain distance from the antenna, to change the time.
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.
If, in each of these ports, a diplexer, which separates the frequency bands of emission and reception, it will be a feeder four ports with a single antenna will be able to send and receive both polarizations simultaneously placed. At other times, these antennas have only two ports, one for emitting a polarization and the other to receive the opposite polarization.
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.
Bandwidth is a frequency range in which the antenna parameters meet certain characteristics. Can define impedance bandwidth, polarization, gain or other parameters. Directivity is the impedance of masts at its terminals. It is the relationship between the voltage and the input current. Z = frac V I. The impedance is a complex number. The real part of an impedance is called mast resistance and the imaginary part is reactance.
A transmitter with more than about 3 items are usually less sensitive in a circle slice perpendicular towards the main direction of a jet and therefore one can put antennas in close proximity to a base station. The distance between the antennas should be at least 1 / 2-1 of main wavelengths used. Further away than about 10 wavelengths (far field) affects largely the antenna radiation pattern, but it can affect radio propagation or radio broadcast.
You can also define the beam width between zero, which is the angular range of the main beam of a radiation pattern between two adjacent zeros to maximum. Create antennas radiated electromagnetic fields. Polarized electromagnetic defined in a certain direction, as the geometric shape that traces the edge of electric field vector at a certain distance from the antenna, to change the time.
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.
If, in each of these ports, a diplexer, which separates the frequency bands of emission and reception, it will be a feeder four ports with a single antenna will be able to send and receive both polarizations simultaneously placed. At other times, these antennas have only two ports, one for emitting a polarization and the other to receive the opposite polarization.
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