The Determination of Dielectric Properties at Very High Frequencies

A simple method of determining the dielectric constant and power factor of solid dielectrics at frequencies as high as 20 megacycles, with an accuracy which is sufficient for most purposes, is described. The major sources of error are discussed in detail, and several precautions which should be observed are pointed out. Measurements of the dielectric properties at 18 megacycles of a number of commonly used materials has shown that in general the power factor and dielectric constant are not widely different from those which obtain at frequencies of the order of one megacycle. In addition, the results of an investigation of the input impedance of vacuum tube voltmeters at high frequencies are described as an illustration of the further application of this method of measurement.