Schematics of the calibration process for the conventional and modified cavity perturbation theories. In comparison with the conventional theory, the modified (this) method employs two known samples to calibrate.
Resonant frequencies versus sample's relative dielectric constant for two calibration conditions: (a) same volume but different dielectric properties and (b) same dielectric property but different volumes. The resonant frequency obtained by HFSS is considered as a standard. The other two curves are calculated using the conventional method (Eq. (1) ) and modified method (Eq. (8) ).
Schematics of experimental setup: (a) heating system (high-power operation) and (b) dielectric measurement system (low-power operation). The temperature was measured with a calibrated infrared thermometer.
(a) Resonant frequency and (b) quality factor versus sample temperature. The sample was heated to 600 °C and allowed it cool down naturally by turning off the microwave power. These data were taken in the cool-down process.
Temperature response for normalized (a) relative dielectric constant ( / ) and (b) loss tangent (tan δs / tan δref) using conventional and modified methods. Red dashed lines with dots are obtained using modified method (Eq. (8) ). Dashed lines with triangles are measured using conventional cavity perturbation method (Eq. (1) ).
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