Barylo H. Structure and parameteric modification of microelectronic impedance signal converters for sensor technology

The thesis is devoted to the problems of creating microelectronic impedance signal converters for sensor technology in order to increase the accuracy of measurements, extend the frequency range of the activating signal, support high-resolution converters. Given the dynamics of the development of modern impedance spectroscopy, which is widely used in the fields of materials science, physics, biophysics, medicine, there is a need for the creation of new integrated, functionally complete analog front-end devices with internet of things. On the basis of the conducted analysis, perspective directions of construction were defined and new approaches and models for the study of the processes of the sinus transformation using the base elements of solid state electronics were proposed. The paper substantiates the use of mathematical and schematic modeling tools using ready-made SPICE models of electronic components provided by their manufacturers and developed their own original models of functionally dependent signal sources, amplifiers, synchronous detectors and integrators. The possibility of using both harmonic and non-harmonic sources of signals of activating sources in the process of measurement is shown, and the regularities of the influence of harmonics of these sources on the accuracy of signal transformation are established. On the basis of the results of model studies, the possibility of significant increase of accuracy is demonstrated by using synchronous detection methods and integration of the informative signal. The generalized structural schemes of construction of converters of galvanostatic and potentiometric methods of measuring impedance and methods of calculating the accuracy of signal transformation are developed. The practical realization of microelectronic impedance converters based on the base elements of solid state electronics was realized and a series of sensory devices for temperature measurement, non-invasive studies of tissues, for the study of the properties of organic semiconductor materials and structures on their basis were created. The fundamental problem that is solved in this paper is the construction of scientific foundations for the creation of high-sensitive, functional microelectronic signal converters of the galvanostatic and potentiometric measurement method for the creation of sensory devices and information-measuring systems.