Optimization of Coating Thickness of Conducting Material on Base Fiber to make it as a Radar Reflector

Chaff is one of the most extensively used passive electronic countermeasure to disrupt radar tracking and are designed to cover wide frequency range from 2-18 GHz. There are various factors to improve backscattered RCS of the chaff cloud at higher frequencies. In this paper, the effect of coating thickness of conducting material of electrically conducting fibre (which is used as chaff) on its backscattered RCS has been studied. The relationship between fiber coating thickness of conducting material and its backscattered RCS were obtained by performing simulations in Ansys HFSS with dipole length of 50mm and 15mm and later validating the same with the measured results. It is observed that with an increase in coating thickness of conducting material of the fibre there is increase in its backscattered RCS. When coating thickness of conducting metal becomes greater than the skin depth of the conducting metal, the increase in observed RCS with increase in coating thickness is marginal. Thus, further increase in coating thickness greater than the skin depth of the conducting metal will not improve the backscattered RCS of the fiber significantly but it will add weight penalty for the fiber.