The invention discloses a method and a device for measuring complex
permittivity of a wave-transmitting material based on a
radiometer, and belongs to the technical field of passive
microwave /
millimeter wave
remote sensing and detection. The method comprises the steps that N (N > = 3) material samples with different thicknesses are prepared, the thicknesses are recorded as d [d1, d2, d3..., dN], and the thicknesses of the samples should be smaller than the
skin depth of the materials, so that it is guaranteed that electromagnetic
waves can effectively penetrate through the samples; measuring the
linear polarization transmittances of the material samples with all the thicknesses under the incident angle theta, and recording the
linear polarization transmittances as gamma [gamma 1, gamma 2, gamma 3... gamma N]; fitting an output loss index factor Q (epsilon r, theta) and a Fresnel
reflectivity Tp (epsilon r, theta) by using a
fitting algorithm according to a calculation formula of the transmissivity of the wave-transparent material; and calculating a complex
dielectric constant epsilon r by using Q (epsilon r, theta) and Tp (epsilon r, theta). The unique solution of the complex
dielectric constant of the wave-transparent material can be obtained, and accurate measurement of the complex
dielectric constant of the wave-transparent material is achieved.