Quadrature may refer to:
In signal processing:
*
Quadrature amplitude modulation
Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signa ...
(QAM), a modulation method of using both an (in-phase) carrier wave and a 'quadrature' carrier wave that is 90° out of phase with the main, or in-phase, carrier
*
Quadrature phase
In physics and mathematics, the phase of a periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is denoted \phi(t) and expressed in such a scale that it v ...
, oscillations that are said to be ''in quadrature'' if they are separated in phase by 90° (/2, or /4)
*
Quadrature filter, the analytic signal of a real-valued filter
*
Quadrature phase-shift keying
Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a constant frequency reference signal (the carrier wave). The modulation is accomplished by varying the sine and cosine inputs at a ...
(QPSK), a phase-shift keying of using four quadrate points on the constellation diagram, equispaced around a circle
In mathematics:
*
Quadrature (mathematics)
In mathematics, quadrature is a historical term which means the process of determining area. This term is still used nowadays in the context of differential equations, where "solving an equation by quadrature" or "reduction to quadrature" means e ...
, drawing a square with the same area as a given plane figure (''squaring'') or computing that area
**
Quadrature of the circle
*
Numerical integration
In analysis, numerical integration comprises a broad family of algorithms for calculating the numerical value of a definite integral, and by extension, the term is also sometimes used to describe the numerical solution of differential equatio ...
is often called 'numerical quadrature' or simply 'quadrature'
**
Gaussian quadrature
In numerical analysis, a quadrature rule is an approximation of the definite integral of a function, usually stated as a weighted sum of function values at specified points within the domain of integration. (See numerical integration for mor ...
, a special case of numerical integration
* Formerly, a synonym for "integral"
**
Integral
In mathematics, an integral assigns numbers to functions in a way that describes displacement, area, volume, and other concepts that arise by combining infinitesimal data. The process of finding integrals is called integration. Along with ...
**
Antiderivative
In calculus, an antiderivative, inverse derivative, primitive function, primitive integral or indefinite integral of a function is a differentiable function whose derivative is equal to the original function . This can be stated symbolica ...
*
Addition in quadrature
In mathematics, Pythagorean addition is a binary operation on the real numbers that computes the length of the hypotenuse of a right triangle, given its two sides. According to the Pythagorean theorem, for a triangle with sides a and b, this lengt ...
, combining the magnitude of uncorrelated signals by taking the square root of the sum of their squares
In physics:
* In
Optical phase space
In quantum optics, an optical phase space is a phase space in which all quantum states of an optical system are described. Each point in the optical phase space corresponds to a unique state of an ''optical system''. For any such system, a plot o ...
, quadratures are operators which represent the real and imaginary parts of the
complex amplitude
Complex commonly refers to:
* Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe
** Complex system, a system composed of many components which may interact with each ...
; see also
in-phase and quadrature components
In electrical engineering, a sinusoid with angle modulation can be decomposed into, or synthesized from, two amplitude-modulated sinusoids that are offset in phase by one-quarter cycle (90 degrees or /2 radians). All three functions have the s ...
In astronomy:
*
Quadrature (astronomy)
In spherical astronomy, quadrature is the configuration of a celestial object in which its elongation is perpendicular to the direction of the Sun. It is applied especially to the position of a superior planet or the Moon at its first and last ...
, the position of a body (moon or planet) such that its elongation is 90° or 270°; i.e., the body-earth-sun angle is 90°
In Hedge-funds:
*
Quadrature (hedge-fund)
Quadrature may refer to:
In signal processing:
*Quadrature amplitude modulation (QAM), a modulation method of using both an (in-phase) carrier wave and a 'quadrature' carrier wave that is 90° out of phase with the main, or in-phase, carrier
*Qua ...
, the quant hedge-fund created in 2010, in London, England.
Quadrature may also refer to:
*
Quadrature encoder
An incremental encoder is a linear or rotary electromechanical device that has two output signals, ''A'' and ''B'', which issue pulses when the device is moved. Together, the ''A'' and ''B'' signals indicate both the occurrence of and direction o ...
, a device that detects mechanical position changes and direction of movement
*
Illusionistic ceiling painting
Illusionistic ceiling painting, which includes the techniques of perspective ''di sotto in sù'' and ''quadratura'', is the tradition in Renaissance, Baroque and Rococo art in which ''trompe-l'œil'', perspective tools such as foreshortening, an ...
, sometimes called ''quadrature'' after the Italian term, ''quadratura''
*
La Quadrature du Net
La Quadrature du Net ('' Squaring the Net'' in French) is a French advocacy group that promotes digital rights and freedoms for its citizens. It advocates for French and European legislation to respect the founding principles of the Internet, m ...
(Squaring of the Net in French), a French advocacy group that promotes digital rights and freedoms of citizens
* "Quadrature", a song by Squarepusher from the album ''
Just a Souvenir
''Just a Souvenir'' is the ninth album by Squarepusher, which was widely released on 27 October 2008. The album had been available to purchase as a download from bleep.com on 15 September 2008.
The album originated in a daydream, in which Tom ...
''
{{disambiguation