Time-domain measurement of dielectric dispersion as a response to pseudorandom noise

Abstract

A new method of measuring the complex permittivity in the time domain is proposed. By taking responses of a sample solution to a binary pseudorandom noise, a simultaneous measurement of all the frequency components are performed. Due to its high efficiency, an extreme reduction in measuring time together with low power excitation becomes possible. The Fourier transform of the response is multiplied by the Fourier transform of the binary pseudorandom noise and normalized; from the transfer function thus obtained, the complex permittivity is calculated, and the dispersion profile is displayed. A measuring time of 28 msec is required to obtain the dielectric dispersion profile from 71 Hz to 36 kHz. This is demonstrated for a solution of poly‐γ‐benzyl L‐glutamate.