Antennas - Antenna Aperture, Antenna Blind Cone, Antenna Diversity, Antenna Feed, Antenna Height Above Average Terrain, Antenna H (Paperback)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 37. Chapters: Antenna aperture, Antenna blind cone, Antenna diversity, Antenna feed, Antenna height above average terrain, Antenna height considerations, Antenna rotator, Aperture-to-medium coupling loss, ArrayComm, Beamwidth, Beam steering, Beam tilt, Bell Laboratories Layered Space-Time, Candelabra, Duo LNB, Effective height, Electrical length, Field strength in free space, Fraunhofer distance, Friis transmission equation, Front-to-back ratio, Ground plane, Half power point, Leaky feeder, Low-noise block downconverter, Macrodiversity, Main lobe, Nantenna, Near and far field, Orthomode transducer, Phase center, Rectenna, Retrodirectivity, Side lobe, Slant range, SSPA, Tunnel transmitter, TV aerial plug, Whip-a-way. Excerpt: The near field (or near-field) and far field (or far-field) and the transition zone are regions of time varying electromagnetic field around any object that serves as a source for the field. The different terms for these regions describe the way characteristics of an electromagnetic (EM) field change with distance from the charges and currents in the object that are the sources of the changing EM field. The more distant parts of the far-field are identified with classical electromagnetic radiation. The basic reason an EM field changes in character with distance from its source is that Maxwell's equations prescribe different behaviors for each of the two source-terms of electric fields and also the two source-terms for magnetic fields. Electric fields produced by charge distributions have a different character than those produced by changing magnetic fields. Similarly, Maxwell's equations show a differing behavior for the magnetic fields produced by electric currents, versus magnetic fields produced by changing electric fields. For these reasons, in the region very close to currents and charge-separations, ...