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
*
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 ...
, oscillations that are said to be ''in quadrature'' if they are separated in phase by 90° (/2, or /4)
*
Quadrature filter
In signal processing, a quadrature filter q(t) is the analytic representation of the impulse response f(t) of a real-valued filter:
:
q(t) = f_(t) = \left(\delta(t) + j\delta(jt) \right) * f(t)
If the quadrature filter q(t) is applied to a signa ...
, the analytic signal of a real-valued filter
*
Quadrature phase-shift keying (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 ...
, 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 equations ...
is often called 'numerical quadrature' or simply 'quadrature'
**
Gaussian quadrature, 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 symbolically ...
*
Addition in quadrature, combining the magnitude of uncorrelated signals by taking the square root of the sum of their squares
In physics:
* In
Optical phase space, quadratures are operators which represent the real and imaginary parts of the
complex amplitude; 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 ...
In astronomy:
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Quadrature (astronomy), 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), the quant hedge-fund created in 2010, in London, England.
Quadrature may also refer to:
*
Quadrature encoder, a device that detects mechanical position changes and direction of movement
*
Illusionistic ceiling painting, 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, ...
(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''
{{disambiguation