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(11) | EP 0 439 337 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Broad-band wave absorber |
| (57) The present invention relates to a broad-band wave absorber wherein plates (3) formed
of a ferrite magnetic material are placed at an optimal spacing and are aligned in
a lattice form in longitudinal and lateral directions on a conductive plate (2). A
magnetic substance of a specific thickness tm is formed into cylindrical blocks of
a height d (where d ≧ tm) wherein an end surface thereof is polygonal, and the cylindrical
blocks are provided with a radio-wave reflecting surface aligned in such a manner
that this surface is perpendicular to the axial direction of the blocks, and the end
surface of the blocks is approximately perpendicular to a direction from which radio
waves are incident. The ferrite magnetic substance could also be formed into rectangular
prisms of thickness 2tm, height d, and length in the longitudinal direction thereof
L, with the prisms aligned at a spacing b on a radio-wave reflecting surface, the
direction of the height dimension of the prisms being approximately parallel to a
radio-wave incidence direction, and the surfaces thereof of the dimensions 2tm and
L being perpendicular to the radio-wave incidence direction, forming a plane parallel
to a magnetic field direction of incident radio waves and the dimension L, wherein
the following relationships hold: L ≧ d ≧ 2tm 20tm ≧ b ≧ 2tm |