Identification of electrical equivalent circuits of research objects by phase-frequency characteristics

Abstract

The paper discusses methods for identifying electrical equivalent circuits of the studied object based on the analysis of phase-frequency and differential phase-frequency characteristics of the output signal in a wide frequency range, using MathCAD software. As a result, the following possibilities are revealed: establishing a method for connecting several electrical links of the same type in a single electrical circuit; identification of topology of bipolar electrical equivalent circuits for parametric sensors of various types, both separately and as part of bipolar electrical circuits; identification of equivalent circuits of metal-insulator-semiconductor (MIS) structures described by equivalent amplitude-frequency characteristics. A technique for the analysis of electrical equivalent circuits is proposed, based on the study of phase characteristics in the coordinates of phase-frequency and differential-frequency dependencies, called by the authors as “phase portraits” of equivalent circuits of the parametric research object, which allowed determining changes in the values of the equivalent circuit elements. This approach is promising from a metrological point of view, since in measuring phase-frequency parameters, frequency being the most stable parameter measured with very high accuracy compared to other analog values, can be used as a measure to increase the objectivity of the analysis result.