Measurements of dielectric properties at Ka-band using a fabry-perot hemispherical open resonator

摘要

A Fabry-Perot hemispherical open resonator is designed and constructed in order to measure dielectric properties of BeO in the Ka-band (26-40 GHz) frequency range. Based on both analytic calculations and simulations by a 3-D finite element of electromagnetic code, HFSS, the hemispherical open resonator is designed to excite a TEM_(0,0,17) mode at 28 GHz. The TEM_(0,0,17) mode is experimentally identified by a field perturbation technique. Dielectric measurements are made by both frequency variation and length variation methods. Measurements show that permittivity and loss tangent of BeO are 6.69 and 6.5 * 10~(-4) - 7.2 * 10~(-4), respectively, in the frequency range of 26-34 GHz.