Anisotropy and local inhomogeneity of dielectric parameters of laminated substrates used for large-size RF-plates

Two problems concerning laminated RF plates are considered - the anisotropy and local inhomogeneity of their dielectric parameters. Three resonance methods are used for the measurement of the longitudinal, transverse and equivalent (in microstrip configuration) dielectric constant and loss tangent. A large number of samples has been extracted from controlled areas in large-size plates of materials such as NH9338, RO4003, etc. The influence of standard deviations of these parameters on microstrip impedance, effective dielectric constant, phase delay, attenuation, etc. is estimated for design purposes.