Quadrature


Quadrature

Quadrature, derived from Latin "quadrare", may refer to:

In signal processing:
*Quadrature amplitude modulation (QAM), a modulation method of using both a carrier wave and a 'quadrature' carrier wave that is 90° out of phase with the main carrier
*Quadrature phase, oscillations that are said to be "in quadrature" if they are separated in phase by 90° (π/2, or λ/4)
*Quadrature filter, the analytic signal of a real-valued filter
*Quadrature coupler, see under chapter five in Power dividers and directional couplers

In mathematics:
*Quadrature of the circle (also "squaring the circle"), in geometry, the problem of constructing a square and circle of equal area, impossible using only an unmarked straight-edge and compass
*"Summing in quadrature" means summing the squares of numbers, then taking the square root, as used in error analysis
*Numerical integration, the numerical calculation of the area under a curve, or more generally, using numerical integration to calculate a definite integral

Quadrature may also refer to:
*In motion control, "quadrature encoder" is a rotary encoder or linear encoder giving both the relative position and the direction of motion of a shaft
*In astronomy, quadrature occurs when two celestial bodies appear 90° apart from one another as viewed from a third celestial body. As an example, the Moon and the Sun are in quadrature with respect to the Earth when the Moon is in its exact first quarter or last quarter phases. The symbol for astronomical quadrature is a hollow square


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Look at other dictionaries:

  • quadrature — [ k(w)adratyr ] n. f. • 1407; bas lat. quadratura 1 ♦ Géom. Opération qui consiste à construire un carré équivalant à une aire donnée. Cour. La quadrature [ kadratyr ] du cercle : faux problème que les géomètres anciens tentaient de résoudre. Fig …   Encyclopédie Universelle

  • Quadrature — Quad ra*ture, n. [L. quadratura: cf. F. quadrature. See {Quadrate}, a.] 1. (Math.) The act of squaring; the finding of a square having the same area as some given curvilinear figure; as, the quadrature of a circle; the operation of finding an… …   The Collaborative International Dictionary of English

  • quadrature — Quadrature. s. f. Reduction de quelque figure à un quarré. Chercher la quadrature du cercle …   Dictionnaire de l'Académie française

  • quadrature — [kwä′drə chər] n. [LL quadratura < L quadratus: see QUADRATE] 1. the act of squaring 2. the construction of a square equal in area to a given surface [the quadrature of a circle] 3. Astron. a configuration of a superior planet or the moon in… …   English World dictionary

  • Quadrature — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. Sur les autres projets Wikimedia : « Quadrature », sur le Wiktionnaire (dictionnaire universel) En mathématiques, une quadrature est le… …   Wikipédia en Français

  • quadrature — (koua dra tu r ) s. f. 1°   Terme de géométrie. Réduction géométrique d une figure curviligne à un carré équivalent en surface. •   Comme les médiocres géomètres ont souvent le malheur de trouver la quadrature exacte du cercle refusée aux autres… …   Dictionnaire de la Langue Française d'Émile Littré

  • QUADRATURE — n. f. Réduction géométrique de quelque figure curviligne à un carré équivalent en surface. La quadrature des courbes. Fig., La quadrature du cercle se dit d’un Problème insoluble. Chercher la quadrature du cercle. QUADRATURE, en termes… …   Dictionnaire de l'Academie Francaise, 8eme edition (1935)

  • QUADRATURE — s. f. (On prononce Coua. ) Réduction géométrique de quelque figure curviligne à un carré équivalent en surface. La quadrature des courbes. La quadrature du cercle est un problème insoluble. QUADRATURE, en termes d Astronomie, Aspect de deux… …   Dictionnaire de l'Academie Francaise, 7eme edition (1835)

  • quadrature — /kwod reuh cheuhr, choor /, n. 1. the act of squaring. 2. Math. a. the act or process of finding a square equal in area to a given surface, esp. a surface bounded by a curve. b. the act or process of finding an area or calculating an integral,… …   Universalium

  • quadrature — kvadratūra statusas T sritis fizika atitikmenys: angl. quadrature vok. Quadratur, f rus. квадратура, f pranc. quadrature, f …   Fizikos terminų žodynas


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