### Abstract

Time-harmonic propagating modes in a perfectly electrically conducting
waveguide with constant cross-section ∂D and axis aligned with the
z-axis have the form u(x,y)e
^{-iωt-iγz}
where the cross-sectional function u satisfies the two-dimensional
Helmholtz equation (Δ+λ)u=0; here k denotes the wavenumber and λ = k
^{2}
-γ
^{2}
. Propagating modes occur at values λ1 ≤ λ2 ≤ λ3 ≤ ... of λ generating
non-trivial solutions of the Helmholtz equation; the cutoff wavenumbers
correspond to setting γ to zero. Now suppose that axially aligned PEC
structures of cross-section Γ are inserted in the waveguide. The
propagation constants are perturbed to values that may be denoted
λ1+Δλ1,λ2+Δλ2,...; the cutoff wavenumbers of the empty waveguide are
correspondingly perturbed. In this paper we present a reliable,
effective and efficient method to obtain the perturbed propagation
constants. It allows us to examine the inclusion of multiple strips
aligned with the z-axis, with the potential for characterizing
propagation in structures with a number of small strip inserts,
metamaterial-filled waveguides and so on.

Language | English |
---|---|

Title of host publication | Proceedings of the 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA) |

Place of Publication | Piscataway, NJ |

Publisher | Institute of Electrical and Electronics Engineers (IEEE) |

Pages | 1049 |

Number of pages | 1 |

ISBN (Electronic) | 9781728105635, 9781728105628 |

ISBN (Print) | 9781728105642 |

DOIs | |

Publication status | Published - 2019 |

Event | 21st International Conference on Electromagnetics in Advanced Applications, ICEAA 2019 - Granada, Spain Duration: 9 Sep 2019 → 13 Sep 2019 |

### Conference

Conference | 21st International Conference on Electromagnetics in Advanced Applications, ICEAA 2019 |
---|---|

Country | Spain |

City | Granada |

Period | 9/09/19 → 13/09/19 |

### Fingerprint

### Cite this

*Proceedings of the 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA)*(pp. 1049). Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE). https://doi.org/10.1109/ICEAA.2019.8879114

}

*Proceedings of the 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA).*Institute of Electrical and Electronics Engineers (IEEE), Piscataway, NJ, pp. 1049, 21st International Conference on Electromagnetics in Advanced Applications, ICEAA 2019, Granada, Spain, 9/09/19. https://doi.org/10.1109/ICEAA.2019.8879114

**Accurate cutoff wavenumbers of a waveguide perturbed by axially aligned inner conductors.** / Smith, Paul D.; Vinogradova, Elena D.; Shestopalov, Yu V.

Research output: Chapter in Book/Report/Conference proceeding › Conference proceeding contribution › Research › peer-review

TY - GEN

T1 - Accurate cutoff wavenumbers of a waveguide perturbed by axially aligned inner conductors

AU - Smith, Paul D.

AU - Vinogradova, Elena D.

AU - Shestopalov, Yu V.

PY - 2019

Y1 - 2019

N2 - Time-harmonic propagating modes in a perfectly electrically conducting waveguide with constant cross-section ∂D and axis aligned with the z-axis have the form u(x,y)e -iωt-iγz where the cross-sectional function u satisfies the two-dimensional Helmholtz equation (Δ+λ)u=0; here k denotes the wavenumber and λ = k 2 -γ 2 . Propagating modes occur at values λ1 ≤ λ2 ≤ λ3 ≤ ... of λ generating non-trivial solutions of the Helmholtz equation; the cutoff wavenumbers correspond to setting γ to zero. Now suppose that axially aligned PEC structures of cross-section Γ are inserted in the waveguide. The propagation constants are perturbed to values that may be denoted λ1+Δλ1,λ2+Δλ2,...; the cutoff wavenumbers of the empty waveguide are correspondingly perturbed. In this paper we present a reliable, effective and efficient method to obtain the perturbed propagation constants. It allows us to examine the inclusion of multiple strips aligned with the z-axis, with the potential for characterizing propagation in structures with a number of small strip inserts, metamaterial-filled waveguides and so on.

AB - Time-harmonic propagating modes in a perfectly electrically conducting waveguide with constant cross-section ∂D and axis aligned with the z-axis have the form u(x,y)e -iωt-iγz where the cross-sectional function u satisfies the two-dimensional Helmholtz equation (Δ+λ)u=0; here k denotes the wavenumber and λ = k 2 -γ 2 . Propagating modes occur at values λ1 ≤ λ2 ≤ λ3 ≤ ... of λ generating non-trivial solutions of the Helmholtz equation; the cutoff wavenumbers correspond to setting γ to zero. Now suppose that axially aligned PEC structures of cross-section Γ are inserted in the waveguide. The propagation constants are perturbed to values that may be denoted λ1+Δλ1,λ2+Δλ2,...; the cutoff wavenumbers of the empty waveguide are correspondingly perturbed. In this paper we present a reliable, effective and efficient method to obtain the perturbed propagation constants. It allows us to examine the inclusion of multiple strips aligned with the z-axis, with the potential for characterizing propagation in structures with a number of small strip inserts, metamaterial-filled waveguides and so on.

UR - http://www.scopus.com/inward/record.url?scp=85074937469&partnerID=8YFLogxK

U2 - 10.1109/ICEAA.2019.8879114

DO - 10.1109/ICEAA.2019.8879114

M3 - Conference proceeding contribution

SN - 9781728105642

SP - 1049

BT - Proceedings of the 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA)

PB - Institute of Electrical and Electronics Engineers (IEEE)

CY - Piscataway, NJ

ER -