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Official Journal of the Japan Wood Research Society

Journal of Wood Science Cover Image
  • NOTE
  • Open Access

Dielectric properties of hardwood species at microwave frequencies

Journal of Wood ScienceOfficial Journal of the Japan Wood Research Society50:575

  • Received: 21 November 2002
  • Accepted: 25 June 2003


Dielectric measurements at 9.8 GHz and 2.45 GHz were made for the three hardwoods Euramerican hybrid poplar, alder, and oriental beech. The method used was based on Von Hippel’s transmission line method. The measurements were carried out at room temperature of 20°–24°C. The dielectric properties of the wood species were determined for the three principal structural directions at six different moisture conditions, covering the range of 0% to 28% moisture content. Results indicated that the behavior of all wood species studied is quantitatively similar. In general, the dielectric properties increase within the range studied with rising moisture content. The grain direction of the wood also plays a significant role.

Key words

  • Dielectric constant
  • Dielectric loss factor
  • Hardwood species
  • Microwave frequencies