Abstract
EM-wave pyramidal-shaped absorbers produced by the traditional smoked roof-tile production process are introduced. In the smoking process, the carbon-coated layer having good electrical conductivity was formed on a dry-shaping pyramid surface made of roof tile clay. It has a superior long-term stability and thermal stability against high power incidence. In this paper, the absorption properties of the absorbers were measured. It is possible to improve the absorption property by controlling the surface resistance of the pyramids. The relationship between EM-wave absorption and surface conductivity are discussed. In addition, pyramidal-shaped absorbers in the millimeter region are developed.