Solid and Particulate Material Permittivity Relationships

The complex permittivities of solid and pulverized samples of two plastics, Rexolite 1422 and Kynar, were measured at frequencies of2 .45 GHz, 11.5 GHz, and 22.0 GHz at 25°C by the short-circuited wave guide technique. Several dielectric mixture equations and extrapolation of functions of the real and imaginary parts of the permittivity that are linear with bulk density were then used to estimate the permittivities at solid-material densitiesfrom measurements on the pulverized samples. For these materials, the best estimates of the permittivities were provided by extrapolations that are consistent with the Complex Refractive Index and Landau and Lifshitz, Looyenga mixture equations. The Boucher mixture equation often gave values very close to the Landau and Lifshitz, Looyenga equation, and theB ruggeman-Hanai, Rayleigh, and Lichtenecker mixture equations gave increasingly larger permittivity estimates in that order.