Definitions
The term "near-field region" (also known as the "near-field" or "near-zone") has the following meanings with respect to different telecommunications technologies:
- The close-in region of an antenna where the angular field distribution is dependent upon the distance from the antenna.
- In the study of diffraction and antenna design, the near-field is that part of the radiated field that is below distances shorter than the Fresnel parameter S = D2/(4λ) from the source of the diffracting edge or antenna of longitude or diameter D.
- In optical fiber communications, the region close to a source or aperture.
Because of these nuances, special care must be taken when comprehending the literature about near-fields and far-fields.
Read more about this topic: Near And Far Field
Famous quotes containing the word definitions:
“The loosening, for some people, of rigid role definitions for men and women has shown that dads can be great at calming babies—if they take the time and make the effort to learn how. It’s that time and effort that not only teaches the dad how to calm the babies, but also turns him into a parent, just as the time and effort the mother puts into the babies turns her into a parent.”
—Pamela Patrick Novotny (20th century)
“Lord Byron is an exceedingly interesting person, and as such is it not to be regretted that he is a slave to the vilest and most vulgar prejudices, and as mad as the winds?
There have been many definitions of beauty in art. What is it? Beauty is what the untrained eyes consider abominable.”
—Edmond De Goncourt (1822–1896)
“What I do not like about our definitions of genius is that there is in them nothing of the day of judgment, nothing of resounding through eternity and nothing of the footsteps of the Almighty.”
—G.C. (Georg Christoph)