Editing Surface wave (section)

===Microwave field theory===
Within microwave field theory, the interface of a dielectric and conductor supports "surface wave transmission". Surface waves have been studied as part of [[transmission line]]s and some may be considered as [[single-wire transmission line]]s.

Characteristics and utilizations of the electrical surface wave phenomenon include:
* The [[field (physics)|field]] components of the wave diminish with distance from the interface.
* Electromagnetic energy is not converted from the surface wave field to another form of energy (except in leaky or lossy surface waves)<ref>{{cite journal| last1= Liu |first1= Hsuan-Hao |last2=Chang |first2=Hung-Chun |title=Leaky Surface Plasmon Polariton Modes at an Interface Between Metal and Uniaxially Anisotropic Materials. |journal=IEEE Photonics Journal |volume=5 |issue=6 |pages=4800806 |date=2013 | bibcode=2013IPhoJ...500806L |doi=10.1109/JPHOT.2013.2288298 | doi-access=free }}</ref> such that the wave does not transmit power normal to the interface, i.e. it is evanescent along that dimension.<ref>Collin, R. E., ''Field Theory of Guided Waves'', Chapter 11 "Surface Waveguides". New York: Wiley-IEEE Press, 1990.</ref> 
* In [[coaxial cable]] in addition to the TEM mode there also exists a transverse-magnetic (TM) mode<ref>{{cite web|url=http://www.corridor.biz/FullArticle.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.corridor.biz/FullArticle.pdf |archive-date=2022-10-09 |url-status=live|title=(TM) mode|website=corridor.biz|access-date=4 April 2018}}</ref> which propagates as a surface wave in the region around the central conductor. For coax of common impedance this mode is effectively suppressed but in high impedance coax and on a single central conductor without any outer shield, low attenuation and very broadband propagation is supported. Transmission line operation in this mode is called [[single-wire transmission line|E-Line]].