Microwave characterization of nanocomposite powders using cavity based optimization approach

A generalized cavity method is presented for accurate characterization of powdered material. Polymer nanocomposites Cu/PEO, SS/PEO and Fe/PEO are synthesized and processed for the preparation of lightweight, cost effective microwave absorbing materials. The variation of dielectric constant and the loss factor are observed with addition of metal particles in the base matrix. The complex permittivity measurement is carried out using the proposed cavity technique which utilizes a new calibration method followed by inverse optimization. The electromagnetic absorption of the resultant nanocomposite is precisely controlled with the filler content variation in the range of 0-30 wt%. It is observed that the loss factor increases with increment in the metal powder content.