Tunable Magnetic Material based Composite Microwave Absorber for Stealth Applications

Microwave-absorbing materials have attracted significant interest over many years for their applications in civilian as well as defense fields. On this account, rigorous research is going on for the development of efficient microwave absorbers. However, it is not easy to develop a tunable microwave absorber as per user demand. Therefore, this paper presents magnetic material-based composites which can be tuned at a particular frequency in the S and C-band on the mixing of particular wt.% of carbonyl iron in milled cobalt powder. Their preparation method is very simple using a high-energy ball mill. The results showed the absorption of all synthesized samples in the S, C, and X-band. The maximum tunability is found to be 63.76% when only 20 wt.% of carbonyl iron was mixed in milled cobalt powder.