The reflection coefficient is used in physics and electrical engineering when wave propagation in a medium containing discontinuities is considered. A reflection coefficient describes either the amplitude or the intensity of a reflected wave relative to an incident wave. The reflection coefficient is closely related to the transmission coefficient. Physics (Greek: (phúsis), nature and (phusiké), knowledge of nature) is the science concerned with the discovery and characterization of universal laws which govern matter, energy, space, and time. ... Electrical Engineers design power systems… … and complex electronic circuits. ... This article is about waves in the most general scientific sense. ... In mathematics, a continuous function is one in which arbitrarily small changes in the input produce arbitrarily small changes in the output. ... Amplitude is a nonnegative scalar measure of a waves magnitude of oscillation, that is, magnitude of the maximum disturbance in the medium during one wave cycle. ... In physics, intensity is a measure of the time-averaged energy flux. ... The reflection of a bridge in Indianapolis, Indianas Central Canal. ... This article is about the transmission coefficient in optics. ...

Different specialties have different applications for the term.

Telecommunications

In telecommunications, the reflection coefficient is the ratio of the amplitude of the reflected wave to the amplitude of the incident wave. In particular, at a discontinuity in a transmission line, it is the complex ratio of the electric field strength of the reflected wave to that of the incident wave. This is typically represented with a Γ (capital gamma). Copy of the original phone of Alexander Graham Bell at the Musée des Arts et Métiers in Paris Telecommunication is the transmission of signals over a distance for the purpose of communication. ... A ratio is a quantity that denotes the proportional amount or magnitude of one quantity relative to another. ... A transmission line is the material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electromagnetic waves or acoustic waves, as well as electric power transmission. ... In mathematics, a complex number is a number of the form where a and b are real numbers, and i is the imaginary unit, with the property i 2 = −1. ... It has been suggested that optical field be merged into this article or section. ... Gamma (uppercase Γ, lowercase γ) is the third letter of the Greek alphabet. ...

The reflection coefficient may also be established using other field or circuit quantities. An electronic circuit is an electrical circuit that also contains active electronic devices such as transistors or vacuum tubes. ...

The reflection coefficient is given by the equations below, where Z₁ is the impedance toward the source, Z₂ is the impedance toward the load: Electrical impedance, or simply impedance, is a measure of opposition to a sinusoidal alternating electric current. ... If an electric circuit has a well-defined output terminal, the circuit connected to this terminal (or its input impedance) is the load. ...

The absolute magnitude of the reflection coefficient (designated by vertical bars) can be calculated from the standing wave ratio, SWR: In mathematics, the absolute value (or modulus[1]) of a real number is its numerical value without regard to its sign. ... In telecommunications, standing wave ratio (SWR) is the ratio of the amplitude of a partial standing wave at an antinode (maximum) to the amplitude at an adjacent node (minimum). ...

The reflection coefficient is displayed graphically using a Smith chart. An impedance Smith chart (with no data plotted) The Smith Chart, invented by Phillip H. Smith (1905-1987),[1][2] is a graphical aid or nomogram designed for electrical and electronics engineers specialising in radio frequency (RF) engineering to assist in solving problems with transmission lines and matching circuits. ...

Source: from Federal Standard 1037C in support of MIL-STD-188 Federal Standard 1037C, entitled Telecommunications: Glossary of Telecommunication Terms is a United States Federal Standard, issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended. ... MIL-STD-188 is a series of U.S. military standards relating to telecommunications. ...

Seismology

See: reflection seismology

Seismic reflection data Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earths subsurface from reflected seismic waves. ...

Optics

Main article: Fresnel equations

In optics, both intensity and amplitude reflection coefficients are used. Typically, the former are represented by a capital R, while the latter are represented by a lower-case r. The Fresnel equations, deduced by Augustin-Jean Fresnel, describe the behaviour of light when moving between media of differing refractive indices. ... Table of Opticks, 1728 Cyclopaedia Optics ( appearance or look in ancient Greek) is a branch of physics that describes the behavior and properties of light and the interaction of light with matter. ...

References

Books

• Bogatin, Eric (2004). Signal Integrity - Simplified. Upper Saddle River, New Jersey: Pearson Education, Inc.. ISBN 0-13-066946-6.  Figure 8-2 and Eqn. 8-1 Pg. 279