Broadband characterisation of engineered dielectric fluids using microstrip ring resonator technique

Characterisation results of the complex permittivity of select dielectric cooling fluids at room temperature and over a broad frequency range found using a low‐loss printed circuit board microstrip ring resonator technique are presented. ANSYS HFSS, a finite‐element full‐wave electromagnetic simulation environment, was used to fit the simulated insertion loss to the calibrated measurements of the microstrip ring resonator in air and submerged in different dielectric fluids. The resulting frequency‐dependent relative permittivity and loss tangent are provided up to 50 GHz for three dielectric cooling fluids: 3M™ Novec™ 649, 3M™ Novec™ HFE‐7100 and 3M™ Fluorinert™ FC‐72.