Microwave Absorption Characteristics of Alumina-Carbon Ceramic Compounds

Part 1 : No-Reflection Analysis

Abstract

Alumina-based electric wave absorbers for 60 GHz were conducted, and their absorbing properties were designed by means of no-reflection analysis based on complex permittivity. Furthermore, the effect of carbon content on the absorbing characteristics was studied.
The result showed that 1.2 mm thickness alumina ceramics including 1.2% carbon provided preferable absorption value of more than 20 dB, which were almost equal to the calculated and designed ones.
This paper describes design and manufacture process, and assessment method of the no-reflection materials.