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The first technique developed was the far-field range, where the antenna under test (AUT) is placed in the far-field of a range antenna. Due to the size required to create a far-field range for large antennas, near-field techniques were developed, which allow the measurement of the field on a distance close to the antenna (typically 3 to 10 ...
The antenna gain, or power gain of an antenna is defined as the ratio of the intensity (power per unit surface area) radiated by the antenna in the direction of its maximum output, at an arbitrary distance, divided by the intensity radiated at the same distance by a hypothetical isotropic antenna which radiates equal power in all directions.
The electrical length of an antenna, like a transmission line, is its length in wavelengths of the current on the antenna at the operating frequency. [1] [12] [13] [4]: p.91–104 An antenna's resonant frequency, radiation pattern, and driving point impedance depend not on its physical length but on its electrical length. [14]
In telecommunications, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). [1]
Most antenna designs are not defined by a physical area but consist of wires or thin rods; then the effective aperture bears no clear relation to the size or area of the antenna. An alternate measure of antenna response that has a greater relationship to the physical length of such antennas is effective length l eff {\displaystyle l_{\text{eff ...
A discone is exceptionally wideband, offering a frequency range ratio of up to approximately 10:1 , over three octaves above the antenna's lowest frequency, but otherwise only functions just as well as other quarter-wave monopoles: It is omnidirectional, vertically polarized, equally efficient as a monopole, and has gain similar to a ground ...
A universal LNB has a switchable local oscillator frequency of 9.75/10.60 GHz to provide two modes of operation: low band reception (10.70–11.70 GHz) and high band reception (11.70–12.75 GHz). The local oscillator frequency is switched in response to a 22 kHz signal superimposed on the supply voltage from the connected receiver.
Vivaldi antennas are useful for any frequency, as all antennas are scalable in size for use at any wavelength. Printed circuit technology makes this type antenna cost effective for microwave frequencies 1 GHz or higher. An inexpensive Vivaldi antenna is etched upon a printed circuit board and fed with a soldered-on coaxial cable and SMA connector.