The aimof this paperwas to investigate the microwave dielectric properties of corn stover at 915 and 2450MHz
from room temperature to 700 °C under nitrogen (N2) environment. Cavity perturbation method was used to
measure the dielectric constant and loss factor. The heating processwas divided into three distinct stages, namely
drying, pyrolysis, and char stage. Dielectric properties during drying and pyrolysis stages were inversely proportional
to the temperature, whereas directly proportional to the temperature in char stage. The maximum microwave
penetration depth of 8.5 m was obtained at 392 °C and 915 MHz, just at the end of the pyrolysis reaction
zone. The experimental data were fitted using regression fit and based on this the dielectric properties model
related to the temperature was developed.