Investigations on microwave characteristics of MgF/sub 2/ at cryogenic temperatures

Abstract

Magnesium Fluoride is a hard and birefringent crystal with low refractive index and a wide transmission range. It is widely used in prisms and optical windows. We have studied the microwave properties of MgF 2 using a Hakki-Coleman dielectric resonator technique. The permittivity varies from 5.026 to 5.165 in the temperature range 15-295K and at a frequency of 32.9 GHz. The loss tangent varies from 1X10 -5 to 8X10 -5 when the temperature increases from 15 K to 295 K.

Low temperature microwave characterisation of lithium fluoride at different frequencies

“…5 at a frequency of 16.5 GHz [7][8][9]. The losses of LiF at microwave frequencies are higher than its counterparts.…”

“…Among the different types of dielectric resonators, Hakki-Coleman (HC) dielectric resonator is commonly used to characterise rod (or cylindrical) shaped dielectric materials at microwave frequencies [7][8][9][10][11][12][13]. The accuracy of measurements using HC dielectric resonator is high but the main difficulty is to machine samples precisely to realize the same height as that of the copper cavity.…”