Absorption properties of novolac-alumina-graphite mixture microwave absorbers in x-band frequencies

الملخص EN

Absorption properties (Attenuation coefficient, the percentage of the reflection, and the percentage of absorption) in x-band have been investigated in this paper for novolac–alumina-graphite mixture.

Using novolac as the host material, the samples are prepared with alumina concentrations (5 %, 10 %, 15 %, 20 %) and graphite concentrations (5 %, 10 %) with thickness equal to 2.2mm.

Network analyzer produced by HP-8510 was used in this work to measure the attenuation coefficient.

The samples (3, 5) have good attenuation of wave with bandwidth of frequencies.

The maximum of attenuation is -25 dB at frequency 10.28GHZ in sample (3) which has concentrations (80 % novolac, 10 % alumina, and 5 % graphite) and -24 dB at frequency 10.56GHZ in sample (5) which has concentrations (75 % novolac, 15 % alumian, and 10 % graphite).

From the results of the attenuation coefficient, the percentage of the reflection is calculated.

The percentage of absorption can be calculated from the percentage of the reflection.