A Lorentzian model as the general case of a frequency-dependent behavior of a dispersive dielectric material is considered in this paper. Recursive convolution algorithms for the finite-difference time-domain (FDTD) technique for two cases of a Lorentzian medium, narrowband and wideband, depending on the ratio of a resonance line half-width at -3 dB and the resonance frequency of the material, are detailed. It is shown that a wideband Lorentzian model of a dielectric FR-4 used in printed circuit boards is more flexible and gives good agreement with experimental curves, and may be preferable as compared to a Debye model.

Meeting Name

IEEE International Symposium on Electromagnetic Compatibility (2002: Aug. 19-23, Minneapolis, MN)


Electrical and Computer Engineering

Research Center/Lab(s)

Electromagnetic Compatibility (EMC) Laboratory

Keywords and Phrases

Debye Model; FDTD Technique; Lorentzian Model; Composite Materials; Dielectric FR-4; Dielectric Materials; Dispersive Dielectric Media; Dispersive Media; Finite Difference Time-Domain Analysis; Finite-Difference Time-Domain Technique; Printed Circuit Boards; Printed Circuit Testing; Recursive Convolution; Resonance Frequency; Resonance Line Half-Width; Wideband Lorentzian Dielectric Dispersive Media

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2002 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Aug 2002