Broadband Dielectric Measurement Techniques (10-6 Hz to 1012 Hz)

The complex dielectric1 function $$ \mathop {\lim }\limits_{x \to \infty } $$ can be measured in the extraordinary broad frequency regime [1-13] from 10-6 Hz up to 1012 Hz (in wavelength$$ 3 \times {10^{16}}cm - 0.03cm $$). To span this dynamic range different measurement systems based on different measurement principles have to be combined (Fig. 2.1) From 10-6 to 107 Hz lumped circuit methods are used in which the sample is treated as a parallel or serial circuit of an ideal capacitor and an ohmic resistor. Effects of the spatial extent of the sample on the electric field distribution are neglected. With increasing frequency the geometrical dimensions of the sample capacitor become more and more important limiting this approach to about 10 MHz. In addition parasitic impedances caused by cables, connectors, etc. become important at frequencies >100 kHz.