Critical Analysis of Periodic Fractal Frequency Selective Surfaces Coupled With Synthesized Ferrite Based Dielectric Substrates for Optimal Radar Wave Absorption

It is a very challenging task to develop a good radar wave absorber with wide bandwidth that corresponds to reflection loss (RL) ≤ − 10 dB and lower coating thickness using radar absorbing material alone. However, this goal can be achieved with the application of advanced electromagnetic (EM) structures such as fractal frequency selective surfaces (FFSSs). The prior knowledge of the suitability of an FFSS for a particular nanocomposite material based on its dielectric constant (ɛ′) is a very crucial factor. Therefore, a critical analysis has been carried out to choose the suitable FFSS geometries for a given set of nanocomposite materials having a ɛ′ ranging in between 1 and 20. The higher iterated Minkowski loop FFSS-impacted nanocomposite has been chosen for the experimental validation based on its good radar wave absorption capability. The Minkowski loop FFSS-impacted radar absorbing coating (RAC) has been fabricated, and its performance evaluation has been carried out. The measured RL of −17.9 dB at 10.8 GHz with a wide bandwidth of 2.9 GHz (RL≤−10 dB) has been noticed for 2.2 mm thick RAC. The findings provide an effective way to develop thin and broadband absorber for various practical EM applications.