Transmission medium

The medium or propagation medium referred to in the wave theory, the substance which is traversed by the waves. While the sound waves require a medium to propagate to electromagnetic waves ( light in a vacuum, for example ) spread out without a medium. A non-homogeneous propagation medium, which limits the propagation of the waves and transmits bundled, is a waveguide.

Electromagnetic waves, optics

An electromagnetic wave propagates in a medium with a speed signal, which is always less than the vacuum speed of light. Each medium causes a ( wavelength-dependent ) attenuation of light. Characteristic of the transmission properties of the medium is the permittivity. In waveguides such as coaxial cables or waveguides further geometrical factors, such as diameter and terminators play a role. Belongs Depending on the wavelength, the description of the propagation of optical or line theory of electrical engineering.

Sound waves, acoustics

Sound waves can propagate in various media, namely in fluids (eg, air, water), or solids ( eg steel). A distinction is therefore fluid sound ( ie, for example, air or water acoustic sound ) and structure-borne noise.

• Wave