THE ELECTROMAGNETIC WAVE ABSORPTION CHARACTERISTIC OF QUASI MICROWAVE BAND IN CARBON MIXED CEMENT MORTAR

摘要

Recently, the equipment machines which an quasimicrowave band is used for is increasing, for example personalhandy phone system and wireless local area network. Thepurpose of this study is to minimize errors and losses of theinformation transmission caused by the electromagnetic wavereflection at the building walls, in using the quasi microwaveband for the data communication. The absorption characteristicof the carbon mixed cement mortar with carbon fiber and that ofthe plain mortar is compared. The electromagnetic materialcoefficient of each cement mortar is measured and theelectromagnetic wave absorption characteristic is simulated.Simulation about not only single layered structural cementmortar but double layered structural one is conducted. Theresults of comparison were shown as follows: it was found thatthe carbon mixed cement mortar had a better absorptioncharacteristic than the plain mortar. The long length fibrouscarbon had a better characteristic than the short fibrous one at alower mixed ratio. Double layered structure with the differentcement mortar in carbon mixed ratio had a better characteristicthan single layered structure, therefore proper layered structureis able to make electromagnetic wave absorber thin. Theabsorption characteristic of the carbon mixed cement mortar andthat of the ferrite mixed cement mortar is compared, theabsorption characteristic of the complex cement mortar withferrite and carbon is examined.