| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayer woody radio wave absorbing board material which is superior in radio wave absorption capability in the vicinity of two wavelength of 2.4 GHz band and 5.2 GHz band, suitable for building materials such as an indoor interior material and a ceiling material, and easy to manufacture at low cost. SOLUTION: A radio wave absorbing board material is constituted by combining and laminating at least two layers of a high dielectric constant layer and at least one layer of a low dielectric constant layer on a metal plate which reflects electromagnetic waves, wherein the high dielectric constant layer includes a woody magnetic board or a woody conductive board of which the dielectric constant in a single layer in 2-6 GHz band is≥2 and≤31, the low dielectric constant layer includes a non-magnetic board or an air layer of which the dielectric constant in a single layer in 2-6 GHz band is≥1 and <2, and the thickness is≥0.6 mm, and wherein the laminate type radio wave absorbing board material has the radio wave absorption capability of≥19 dB within a whole band of 2-6 GHz (bandwidth being 4 GHz). The woody board is produced by joining wooden powder and magnetic powder or conductive powder by a binder resin and then press-forming them. COPYRIGHT: (C)2011,JPO&INPIT |
