Isotropic material properties are density, electrical conductivity, magnetic permeability or their refraction, which are independent of direction and do not change with direction or distance. Due to these properties, electric, magnetic or electromagnetic fields propagate uniformly in all directions. The Duden defines isotropic as "having the same physical and chemical properties in all directions".
In the context of ITWissen topics, the term isotropic is used for radio and sound radiation. The term isotropic is therefore used for antennas and loudspeakers, but also for the liquid crystal structures of LCD displays.
- An isotropic antenna is a theoretical antenna model, comparable to a lossless spherical radiator. Such an antenna model is a reference antenna that radiates uniformly in all directions and has an optimal energy field. The level of an isotropic omnidirectional antenna is given in decibels isotropic( dBi), where 0 dBi is the reference level for calculating the antenna gain from other antennas. The power density depends on the antenna distance (r), but is independent of the radiation angle. It is calculated from the radiated power (Pt) of the antenna divided by the spherical surface at radius (r), `(Pt)/(4Pi)* r^2`.
- Sound radiation is about loudspeakers radiating sound omnidirectionally in as many directions as possible, as a spherical wave.
- Regarding the properties of liquid crystals, isotropic liquid crystals have the aggregate states: solid - liquid - gaseous.
In contrast to the isotropic properties are anisotropic ones. This applies equally to the change in the aggregate states of liquid crystals and to the propagation of sound waves and electromagnetic waves.