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2.4 GHz helical antenna radiation pattern (NEC simulation) The Numerical Electromagnetics Code, or NEC, is a popular antenna modeling computer program for wire and surface antennas. It was originally written in FORTRAN during the 1970s by Gerald Burke and Andrew Poggio of the Lawrence Livermore National Laboratory. The code was made publicly ...
Antenna modeling, especially in Amateur Radio. Widely used as the basis for many GUI-based programs on many platforms. Widely used as the basis for many GUI-based programs on many platforms. Version 2 is open source, but Versions 3 and 4 are commercially licensed.
Another more recent horn-reflector design is the cass-horn, which is a combination of a horn with a cassegrain parabolic antenna using two reflectors. [ 25 ] 15-meter (50 ft) Holmdel horn antenna at Bell Labs in Holmdel, New Jersey, USA, with which Arno Penzias and Robert Wilson discovered cosmic microwave background radiation in 1964.
The top shows the directive pattern of a horn antenna, the bottom shows the omnidirectional pattern of a simple vertical dipole antenna. In the field of antenna design the term radiation pattern (or antenna pattern or far-field pattern) refers to the directional (angular) dependence of the strength of the radio waves from the antenna or other ...
For such an antenna, the near field is the region within a radius r ≪ λ, while the far-field is the region for which r ≫ 2 λ. The transition zone is the region between r = λ and r = 2 λ . The length of the antenna, D, is not important, and the approximation is the same for all shorter antennas (sometimes idealized as so-called point ...
TICRA (name derived from the last syllable of the first word and first syllable of the second word in Electromagnetic radiation) is a company in Copenhagen, Denmark specializing in antenna analysis and synthesis software as well as related consultancy services. Their signature software is TICRA Tools, which has 6 individual software packages ...
A scheme and radiation pattern of a log-spiral antenna, designed with a NEC-based modeling software. In the 1960s, early research work on the method was published by Kenneth Mei, Jean van Bladel [12] and Jack Richmond. [13]
Bell Labs' horn antenna, April 2007. The horn antenna at Bell Telephone Laboratories in Holmdel, New Jersey, was constructed on Crawford Hill in 1959 to support Project Echo, the National Aeronautics and Space Administration's passive communications satellites, [8] [5] which used large aluminized plastic balloons (satellite balloon) as reflectors to bounce radio signals from one point on the ...