Measurements of dielectric losses in uniaxial and biaxial crystals

摘要

The majority of high quality materials produced by industry are anisotropic crystals. So, for their certification it is important to know not only integral losses (average volume of whole dielectric material), but the dependence of the dielectric losses upon the detachment of the crystal directions (upon the main directions, for example). The electrodynamic and numerical Q-factor calculations of H- and E-modes of a rectangular waveguide junction, filled by tetragonal uniaxial crystals and rhombic biaxial crystals, have been carried out in this work. The methods of the anisotropic substrate dielectric losses for non-destructive measurements along the main directions of the crystal dielectric permittivity tensor have been created. The aim of this work is to calculate the Q-factor of H/sub 110/ and E/sub 110/ modes of a wave junction based on rectangular waveguides. During the calculation of the Q/sub 0//sup E,H/ the losses in the walls of the waveguides were taken into consideration, that form the junction (R/sub S/-surface waveguide walls resistance, R/sub Sm/-surface waveguide copper walls resistance) and dielectric losses /spl epsi/" (/spl epsi/=/spl epsi/'-i/spl epsi/") along the main directions of the crystal.