### Abstract

Multiwalled carbon nanotubes (MWNTs) are characterized at X-, Ku-, Ka-, and Q-bands by rectangular waveguide measurements. The scattering parameters (S-parameters) of thin MWNT papers containing a large ensemble of randomly oriented nanotubes are measured by a vector network analyzer from 8 to 50 GHz. A rigorous extraction algorithm has been developed to compute the effective complex permittivity (ε = ε′ -jε″) and permeability (μ = μ′ -jμ″) of the nanotube papers from the measured S-parameters. The extracted effective medium parameters are verified by finite-element simulations using Ansoft's High Frequency Structure Simulator (HFSS). The uncertainties for this characterization method are analyzed. The systematic uncertainties are found larger at lower frequencies than at higher frequencies. The extracted conductivity of the nanotube papers is in the range of 810-1500 S/m and the dielectric constant is from 250 to 700. The extracted complex permittivity can be fitted with the Drude-Lorentz model for the 8-50-GHz frequency range. The effective medium theory is then applied to remove the impact of air in the nanotube paper.

Original language | English (US) |
---|---|

Pages (from-to) | 499-506 |

Number of pages | 8 |

Journal | IEEE Transactions on Microwave Theory and Techniques |

Volume | 56 |

Issue number | 2 |

DOIs | |

State | Published - Feb 2008 |

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### Keywords

- Conductivity
- Drude model
- Drude-Lorentz model
- Effective medium theory
- Multiwalled carbon nanotube (MWNT)
- Permeability
- Permittivity
- Waveguide

### ASJC Scopus subject areas

- Electrical and Electronic Engineering

### Cite this

**Microwave (8-50 GHz) characterization of multiwalled carbon nanotube papers using rectangular waveguides.** / Wang, Lu; Zhou, Rongguo; Xin, Hao.

Research output: Contribution to journal › Article

*IEEE Transactions on Microwave Theory and Techniques*, vol. 56, no. 2, pp. 499-506. https://doi.org/10.1109/TMTT.2007.914627

}

TY - JOUR

T1 - Microwave (8-50 GHz) characterization of multiwalled carbon nanotube papers using rectangular waveguides

AU - Wang, Lu

AU - Zhou, Rongguo

AU - Xin, Hao

PY - 2008/2

Y1 - 2008/2

N2 - Multiwalled carbon nanotubes (MWNTs) are characterized at X-, Ku-, Ka-, and Q-bands by rectangular waveguide measurements. The scattering parameters (S-parameters) of thin MWNT papers containing a large ensemble of randomly oriented nanotubes are measured by a vector network analyzer from 8 to 50 GHz. A rigorous extraction algorithm has been developed to compute the effective complex permittivity (ε = ε′ -jε″) and permeability (μ = μ′ -jμ″) of the nanotube papers from the measured S-parameters. The extracted effective medium parameters are verified by finite-element simulations using Ansoft's High Frequency Structure Simulator (HFSS). The uncertainties for this characterization method are analyzed. The systematic uncertainties are found larger at lower frequencies than at higher frequencies. The extracted conductivity of the nanotube papers is in the range of 810-1500 S/m and the dielectric constant is from 250 to 700. The extracted complex permittivity can be fitted with the Drude-Lorentz model for the 8-50-GHz frequency range. The effective medium theory is then applied to remove the impact of air in the nanotube paper.

AB - Multiwalled carbon nanotubes (MWNTs) are characterized at X-, Ku-, Ka-, and Q-bands by rectangular waveguide measurements. The scattering parameters (S-parameters) of thin MWNT papers containing a large ensemble of randomly oriented nanotubes are measured by a vector network analyzer from 8 to 50 GHz. A rigorous extraction algorithm has been developed to compute the effective complex permittivity (ε = ε′ -jε″) and permeability (μ = μ′ -jμ″) of the nanotube papers from the measured S-parameters. The extracted effective medium parameters are verified by finite-element simulations using Ansoft's High Frequency Structure Simulator (HFSS). The uncertainties for this characterization method are analyzed. The systematic uncertainties are found larger at lower frequencies than at higher frequencies. The extracted conductivity of the nanotube papers is in the range of 810-1500 S/m and the dielectric constant is from 250 to 700. The extracted complex permittivity can be fitted with the Drude-Lorentz model for the 8-50-GHz frequency range. The effective medium theory is then applied to remove the impact of air in the nanotube paper.

KW - Conductivity

KW - Drude model

KW - Drude-Lorentz model

KW - Effective medium theory

KW - Multiwalled carbon nanotube (MWNT)

KW - Permeability

KW - Permittivity

KW - Waveguide

UR - http://www.scopus.com/inward/record.url?scp=38849119722&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=38849119722&partnerID=8YFLogxK

U2 - 10.1109/TMTT.2007.914627

DO - 10.1109/TMTT.2007.914627

M3 - Article

AN - SCOPUS:38849119722

VL - 56

SP - 499

EP - 506

JO - IEEE Transactions on Microwave Theory and Techniques

JF - IEEE Transactions on Microwave Theory and Techniques

SN - 0018-9480

IS - 2

ER -