Metamaterial Absorber based on Minkowski Fractal Patch for Stealth Applications

Radar absorbing structures (RAS) have gained significant importance in aerospace domain with the advent of stealth technology. However, it is still a challenging task to achieve high levels of power absorption over a broad range of frequencies with minimum thickness. Advanced electromagnetic techniques like application of frequency selective surfaces (FSS) are attractive options for obtaining superior absorption characteristics at reduced thickness. However, FSS-based absorbers using patches as unit cell are usually narrowband due to resonance conditions. In this regard, the present paper proposes a novel metamaterial absorber based on Minkowski fractal patch configuration for X-band applications. Several unit cells with dimensions optimized for resonance at closely spaced frequencies have been used in a single absorber. The full wave simulation results clearly illustrate the broadening of bandwidth accomplished using dimensionally different fractals arranged appropriately on the absorber.