A novel approach for measuring inhomogeneous and irregular dielectric plate at millimeter-wavelengths

A novel approach, which is based on an improved reverse-microscope system (IRMS), for measuring inhomogeneity and irregularity of dielectric plate was proposed and simulated at millimeter wavelengths. The IRMS is designed carefully so as to produce a thin beam, which occupy a smaller area than Gaussian beam does. Both finite difference time domain (FDTD) method and finite element method (FEM) are used to verify the validity of IRMS with higher spatial resolution. Therefore, the IRMS can be used to measure the permittivity and thickness of the plate, which may be different from cell to cell and may not be in planar form. Then numerical simulation results based on the FDTD method were presented, which is depicted as images to show the variance of the permittivity and thickness of dielectric plate and compared with that from Gaussian beam. The advantage of IRMS over Gaussian beam is demonstrated.