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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 ...
The far-field pattern of an antenna may be determined experimentally at an antenna range, or alternatively, the near-field pattern may be found using a near-field scanner, and the radiation pattern deduced from it by computation. [1] The far-field radiation pattern can also be calculated from the antenna shape by computer programs such as NEC.
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 ...
Science fiction (sometimes shortened to sci-fi or abbreviated SF) is a genre of speculative fiction which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel universes, and extraterrestrial life.
The far-field region is far enough from the antenna to ignore its size and shape: It can be assumed that the electromagnetic wave is purely a radiating plane wave (electric and magnetic fields are in phase and perpendicular to each other and to the direction of propagation). This simplifies the mathematical analysis of the radiated field.
Sometimes the far future genre moves from science fiction to fantasy, showing a society where civilization has regressed to the point where older technologies are no longer understood and are seen as magic. This subgenre is sometimes known as the "far future fantasy" [2] and partially overlaps with the science fantasy genre. [3]
Energy shield from the game Second Life. In speculative fiction, a force field, sometimes known as an energy shield, force shield, energy bubble, or deflector shield, is a barrier produced by something like energy, negative energy, dark energy, electromagnetic fields, gravitational fields, electric fields, quantum fields, telekinetic fields, plasma, particles, radiation, solid light, magic, or ...
Unlike the works about the far future, set thousands or more years in the future and often tackling philosophical concepts such as the ultimate fate of the universe, fiction set in the near future, roughly defined as within the next few years or decades, α has been described as more realistic and containing themes that have been described as more socially relevant.