Hemispherical X band microwave small sized open resonator for wide range from 1 to 20 permittivity characterization of solid-state dielectrics

We carried out the computer simulation and experimental study of the Fabry-Perot open hemispherical resonator of the X band with the following characteristics: one resonator mirror has semispherical shape and another one is a plane mirror and it has much smaller diameter than the first mirror. The working resonant mode is TEM005, i.e., only 5 semi-waves are located between the hemispherical and plane resonator mirrors. The resonator has quite sparse frequency spectrum such as 3 resonances in the 7-12 GHz range. At the permittivity variation of the permittivity of dielectric samples from 1 to 20 units the corresponding resonant frequency range is quite large and is equal to 1.4 GHz. The quality factor of the resonator at resonant frequencies is in the range 100--600, and it is enough to determine the permittivity of dielectric samples placed on the plane mirror. The dielectric samples diameter is rather small and is equal to 50 mm and its height is 5 mm. The computer simulation results are in good agreement to the experimental ones. The resonant frequency and Q factor differences between the experimental and calculation values are in average of 100 MHz and 4 units, respectively, for samples measurement. Published under an exclusive license by AIP Publishing.