Measurement of High Permittivity Values at Centimetre Wave-lengths

Abstract

CERAMIC materials with permittivity values up to several thousand are now available. The measurement of permittivities of this order provides little difficulty at normal radio frequencies, but measurements have not been made, so far as I am aware, at frequencies of the order of 10¹⁰ c./s. (λ = 3 cm.)¹, in which frequency region the materials are likely to find increasing application. For this purpose the experimental technique illustrated in Fig. 1 has been developed. A specimen of the material is placed in a coaxial line or wave-guide (completely filling the dielectric space) and is followed by a non-reflecting termination. The energy transmitted through the specimen is measured at A, for constant incident energy, as the wave-length of the energy source is varied.