Catalyzed Mechanism for Microwave Absorption in Composite Barriers

  • Ahmed K. Abed Electrical and Electronic Dept. College of Engineering University of Thi-Qar
  • S S. Abdul Noor Applied Science Department University of Technology
  • A M. Jasim Research and Development Department Ministry of Sciences and Technology


A series of two-layered composite barriers filled with (10% carbon black) were produced,
with their second layers loaded with foreign dispersion acting in aid of the microwave absorption
process. Fixed weights of chopped copper wires with lengths (1,3,5) mm were dispersed in the
above mentioned barriers. The resulting behavior indicates that these catalyst dispersion played a
very useful role in enhancing the absorption of the barrier. Moreover, certain wire lengths
exhibited an optimum behavior at various frequencies, suggesting that these wires act as short
dipole antennas which convert the microwave signal into a leaked current. Mixing various wire
lengths yielded a (100% bandwidth covering the whole of the X-band fore reflectivity level less
than –11dB). Also various concentrations of AL-powders were dispersed in these second layers
and an optimum concentration exhibited a low reflectivity level over the whole X-band.
Intermixing of wires and powders produced a rather poor behavior suggesting that this might be
due to the metallic over exceeded presence in the barrier.