Dielectric Measurement of Substrate Materials Using 3D Printed Re-Entrant Cavity Resonator

Modified re-entrant cavity has been designed and fabricated using 3D printing for dielectric characterisation of substrate materials at 2 GHz. The cavity has the capability of measuring the dielectric constant of solid sample of various thickness. A mathematical model based on simulation has been developed and utilised for the extraction of the dielectric property. Several samples of substrates of 20 mm in diameter have been measured using the designed cavity resonator. The results obtained have good agreement with values reported in literature. An uncertainty analysis of measurements is also provided. The method is promising for measurement of low dielectric and low loss material for industrial application.