MICROWAVE CHARACTERIZATION OF BIO-COMPOSITES MATERIALS BASED FINITE ELEMENT AND NICHOLSON–ROSS–WEIR METHODS

Abstract

In this work, Bio-composite of oil palm empty fruit bunch fibre (OPEFB)-filler andpolycaprolactone (PCL)-polymer has been prepared and characterized. The functional groups and morphology of theprepared samples were characterized by Fourier transform infrared spectroscopy (FT-IR). By using the NicholsonRoss-Weir(NRW) mode, both of real and imaginary relative permittivity values of the samples were obtainedsimultaneously from the reflection and transmission coefficient measurements of the materials. Whereas, theattenuation with the field distribution at the waveguide filled with a sample were considered by using the FiniteElement Method (FEM). The magnitude of the reflection and transmission (R/T) coefficients of the composite withdifferent filler percentages were measured using rectangular waveguide in conjunction with a microwave vectornetwork analyzer (VNA) in X-band range of frequency. The computations of the S-parameters were achieved byusing the FEM technique along with NRW mode. Then, the obtained results were compared with the measured R/Tcoefficients. Relative error results nominated the FEM mode due to its highly accurate results than the other method. Keywords: Microwave measurements, OPEFB, PCL, Bio-composite