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Mode (electromagnetism)

The mode of electromagnetic systems describes the field pattern of the propagating waves.{{Cite book |last=Jackson |first=John David |title=Classical electrodynamics |date=1975 |publisher=Wiley |isbn=978-0-471-43132-9 |edition=2d |location=New York}}{{rp|369|q=...the electromagnetic fields in a hollow guide are described by an infinite set of characteristic or normal modes...}}

Some of the classifications of electromagnetic modes include;

  • Modes in waveguides and transmission lines. These modes are analogous to the normal modes of vibration in mechanical systems.{{rp|loc=A.4|q=Physically, the wave function ψ represents the so-called eigenvalue or normal mode solutions for the “TM modes” of a rectangular cavity.}}
  • Transverse modes, modes that have at least one of the electric field and magnetic field entirely in a transverse direction.{{rp|52}}
  • Transverse electromagnetic mode (TEM), as with a free space plane wave, both the electric field and magnetic field are entirely transverse.
  • Transverse electric (TE) modes, only the electric field is entirely transverse. Also notated as H modes to indicate there is a longitudinal magnetic component.
  • Transverse magnetic (TM) modes, only the magnetic field is entirely transverse. Also notated as E modes to indicate there is a longitudinal electric component.
  • Hybrid electromagnetic (HEM) modes, both the electric and magnetic fields have a component in the longitudinal direction. They can be analysed as a linear superposition of the corresponding TE and TM modes.{{rp|550}}
  • HE modes, hybrid modes in which the TE component dominates.
  • EH modes, hybrid modes in which the TM component dominates.
  • Longitudinal-section modes{{rp|294}}
  • Longitudinal-section electric (LSE) modes, hybrid modes in which the electric field in one of the transverse directions is zero
  • Longitudinal-section magnetic (LSM) modes, hybrid modes in which the magnetic field in one of the transverse directions is zero
  • The term eigenmode is used both as a synonym for mode{{Cite book |last1=Rothwell |first1=Edward J. |title=Electromagnetics |last2=Cloud |first2=Michael J. |date=2001 |publisher=CRC Press |isbn=978-0-8493-1397-4 |series=Electrical engineering textbook series |location=Boca Raton, Fla}}{{rp|loc=5.4.3|q=...the transverse behavior of the waveguide fields. When coupled with an appropriate boundary condition, this homogeneous equation has an infinite spectrum of discrete solutions called eigenmodes or simply modes.}} and as the eigenfunctions in a eigenmode expansion analysis of waveguides.{{Cite journal |last1=Huang |first1=Shaode |last2=Pan |first2=Jin |last3=Luo |first3=Yuyue |date=2018 |title=Study on the Relationships between Eigenmodes, Natural Modes, and Characteristic Modes of Perfectly Electric Conducting Bodies |journal=International Journal of Antennas and Propagation |language=en |volume=2018 |pages=1–13 |doi=10.1155/2018/8735635 |doi-access=free |issn=1687-5869|hdl=10453/132538 |hdl-access=free }}
  • Similarly natural modes arise in the singular expansion method of waveguide analysis and characteristic modes arise in characteristic mode analysis.
  • Modes in other structures
  • Bloch modes, modes of Bloch waves; these occur in periodically repeating structures.{{rp|291}}

Mode names are sometimes prefixed with quasi-, meaning that the mode is not quite pure. For instance, quasi-TEM mode has a small component of longitudinal field.{{rp|123}}

References

{{reflist|refs=

{{Cite book |last=Connor |first=F. R. |title=Wave transmission |date=1972 |publisher=Edward Arnold |isbn=978-0-7131-3278-6 |series=His Introductory topics in electronics and telecommunication |location=London}}

{{Cite book |last1=Edwards |first1=T. C. |title=Foundations for microstrip circuit design |last2=Steer |first2=Michael Bernard |date=2016 |publisher=IEEE Press, Wiley |isbn=978-1-118-93619-1 |edition=Fourth|location=Chichester, West Sussex, United Kingdom}}

{{Cite book |last=Yang |first=Jianke |title=Nonlinear waves in integrable and nonintegrable systems |date=2010 |publisher=Society for Industrial and Applied Mathematics |isbn=978-0-89871-705-1 |series=Mathematical modeling and computation |location=Philadelphia}}

{{Cite book |last=Chen |first=Wai Kai |title=The Electrical Engineering Handbook |date=2004 |publisher=Elsevier |isbn=0-0804-7748-8}}

{{Cite book |last1=Zhang |first1=Kequian |url=http://link.springer.com/10.1007/978-3-540-74296-8 |title=Electromagnetic Theory for Microwaves and Optoelectronics |last2=Li |first2=Dejie |publisher=Springer Berlin Heidelberg |year=2008 |isbn=978-3-540-74295-1 |location=Berlin, Heidelberg |language=en |doi=10.1007/978-3-540-74296-8}}

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Category:Wave mechanics

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