  The theoretical model is fully developed and the test rig is designed for the
measurements of microwave parameters of unclad and laminated dielectric
substrates. The geometry of the electromagnetic field in the resonator allows
dielectric measurements with electric field component orthogonal to the sample
surface. The test rig was completely automatized for measurements of the
following parameters: (i) dielectric constant of the dielectric substrate in
the range from 2 to 10, (ii) loss tangent of the dielectric substrate in the
range from 10^-4 to 10^-2, and (iii) microwave ohmic loss at the interface
between the metal layer and the dielectric material in the range from 0.01 to
0.2 Ohm.Measurements for a number of commonly-used microwave PCB materials were
performed in the frequency range from 30 to 40 GHz and over a temperature range
from -50C to +70C.
