Coupling (electronics)
Encyclopedia
In electronics
and telecommunication
, coupling is the desirable or undesirable transfer
of energy from one medium
, such as a metallic wire or an optical fiber
, to another medium, including fortuitous transfer.
Coupling is also the transfer of electrical energy from one circuit segment to another. For example, energy is transferred from a power source
to an electrical load by means of conductive coupling
, which may be either resistive
or hard-wire
. An AC potential may be transferred from one circuit segment to another having a DC potential by use of a capacitor
. Electrical energy may be transferred from one circuit segment to another segment with different impedance
by use of a transformer. This is known as impedance matching. These are examples of electrostatic
and electrodynamic inductive coupling.
Electromagnetic induction:
Electromagnetic radiation:
Other kinds of energy coupling:
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
and telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
, coupling is the desirable or undesirable transfer
Transfer
Transfer may refer to:* Transfer * Transfer * Transfer DNA, the transferred DNA of the tumor-inducing plasmid of some species of bacteria such as Agrobacterium tumefaciens* Transfer...
of energy from one medium
Transmission medium
A transmission medium is a material substance that can propagate energy waves...
, such as a metallic wire or an optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
, to another medium, including fortuitous transfer.
Coupling is also the transfer of electrical energy from one circuit segment to another. For example, energy is transferred from a power source
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
to an electrical load by means of conductive coupling
Conductive coupling
Conductive coupling is the transfer of electrical energy by means of physical contact via a conductive medium, in contrast to inductive coupling and capacitive coupling...
, which may be either resistive
Resistor
A linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...
or hard-wire
Wire
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...
. An AC potential may be transferred from one circuit segment to another having a DC potential by use of a capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
. Electrical energy may be transferred from one circuit segment to another segment with different impedance
Characteristic impedance
The characteristic impedance or surge impedance of a uniform transmission line, usually written Z_0, is the ratio of the amplitudes of a single pair of voltage and current waves propagating along the line in the absence of reflections. The SI unit of characteristic impedance is the ohm...
by use of a transformer. This is known as impedance matching. These are examples of electrostatic
Capacitive coupling
In electronics, capacitive coupling is the transfer of energy within an electrical network by means of the capacitance between circuit nodes. This coupling can have an intentional or accidental effect...
and electrodynamic inductive coupling.
Types of coupling
Electrical conduction:- hard-wireWireA wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...
- resistiveResistorA linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...
- natural conductor
Electromagnetic induction:
- electrodynamic -- commonly called inductive coupling, also magnetic coupling
- electrostaticCapacitive couplingIn electronics, capacitive coupling is the transfer of energy within an electrical network by means of the capacitance between circuit nodes. This coupling can have an intentional or accidental effect...
-- commonly called capacitive coupling - evanescent wave coupling
Electromagnetic radiation:
- radioRadio wavesRadio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 GHz to as low as 3 kHz, and corresponding wavelengths from 1 millimeter to 100 kilometers. Like all other electromagnetic waves,...
-- wireless telecommunications - electromagnetic interferenceElectromagnetic interferenceElectromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
(EMI) -- Sometimes called radio frequency interference (RFI), is unwanted coupling. Electromagnetic compatibilityElectromagnetic compatibilityElectromagnetic compatibility is the branch of electrical sciences which studies the unintentional generation, propagation and reception of electromagnetic energy with reference to the unwanted effects that such energy may induce...
(EMC) requires techniques to avoid such unwanted coupling, such as electromagnetic shieldingElectromagnetic shieldingElectromagnetic shielding is the process of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive and/or magnetic materials. Shielding is typically applied to enclosures to isolate electrical devices from the 'outside world' and to cables to isolate...
. - Microwave power transmission
Other kinds of energy coupling:
- acousticAcoustic couplerIn telecommunications, the term acoustic coupler has the following meanings:# An interface device for coupling electrical signals by acoustical means—usually into and out of a telephone instrument....
See also
- antenna noise temperatureAntenna noise temperatureIn telecommunication, antenna noise temperature is the temperature of a hypothetical resistor at the input of an ideal noise-free receiver that would generate the same output noise power per unit bandwidth as that at the antenna output at a specified frequency....
- coupling lossCoupling lossCoupling loss also known as connection loss is the loss that occurs when energy is transferred from one circuit, circuit element, or medium to another...
- directional coupler
- equilibrium length
- fiber-optic coupling
- loading coilLoading coilIn electronics, a loading coil or load coil is a coil that does not provide coupling to any other circuit, but is inserted in a circuit to increase its inductance. The need was discovered by Oliver Heaviside in studying the disappointing slow speed of the Transatlantic telegraph cable...
- shield
- list of electronics topics
- AC Coupling
- impedance matchingImpedance matchingIn electronics, impedance matching is the practice of designing the input impedance of an electrical load to maximize the power transfer and/or minimize reflections from the load....
- impedance bridgingImpedance bridgingIn electronics, especially audio and sound recording, a high impedance bridging, voltage bridging, or simply bridging connection is one which maximizes transfer of a voltage signal to the load...
- decoupling