About permittivity anisotropy in lanthanum aluminate single crystal substrates

The results of the microwave study on the dielectric properties of substrates from the LaAlO3 monocrystal within the frequency range of 20-28 GHz are presented. The resonator in form of intersection of the beyond-the-limit circular and radial waveguides with the main polarization-degenerated type of oscillations is used. The anisotropy, changing with the limits of the Δε=0.1-0.9 is identified in various monocrystal samples in the plane (100). The obtained data show, that by developing and manufacturing the microwave devices on the basis of the HTSC films, applied on the substrates from the LaAlO3 monocrystal, the latter require the microwave monitoring of the dielectric properties before the subsequent application of the HTSC films