transversal electromagnetic mode (TEM)
Transverse waves are electromagnetic waves, Transversal Electomagnetic Mode (TEM), which are characterized by a special radiation pattern. In transverse waves, the electric field, the E-field, and the magnetic field, the H-field, are perpendicular to each other. E waves have electric field components but no magnetic field components.
The magnetic fields are perpendicular to the direction of propagation. H-waves, on the other hand, have magnetic field components, and the electric fields are transverse to the direction of propagation. The transverse waves are generated by alternating magnetic and electric fields. Both waves are out of phase with each other, vary independently in strength, and are at right angles to the direction of propagation. Neither electric nor magnetic fields occur in the direction of propagation.
In the transverse wave, the amplitude of the H-field and that of the E-field are dependent on each other via the impedance of free space. The transverse form of propagation occurs with high- frequency waves and microwaves transmitted in waveguides. But also with light in optical waveguides and in opticalresonators. In addition, there are so-called TEM cells, which are rectangularly expanded coaxial lines for generating transverse electric fields. They are used, for example, to study electromagnetic compatibility( EMC) and immunity to interference.