Dielectric constant and loss tangent in LiNbO3 crystals from 90 to 147 GHz

The complex dielectric constant epsilon(omega) of poled LiNbO3 crystals has been measured from 90 to 147 GHz using a reflectometer bridge. Electric field polarizations in both the ordinary and extraordinary axes were studied. The real part of epsilon(omega) differs only slightly from its value near 10 GHz, while the imaginary part is significantly larger than reported at lower frequencies. The data are used to model the dissipative losses of a gold co-planar waveguide on LiNbO3. (C) 2001 American Institute of Physics.