Current state and development trends of class E oscillators: an overview

Abstract

An analysis of the current state of power generators of the class E family was carried out. They include classes: inverse E (E-1), with an injection of harmonics – class EM, hybrid classes E/Fn and EFn, including those built based on an active distributed transformer scheme. New developments of such oscillators over the past five years are considered. Significant progress has been made in the development of new feedback schemes. The study of oscillator schemes with power summation and the use of synchronized oscillators is considered. In connection with the appearance of new active devices, circuits using additional active elements – drivers of powerful transistors and the use of two-stroke circuits for the construction of a class E oscillator key are spreading. The proposed classification of oscillators is based on the principle of building an output circuit and a feedback circuit, the morphological table of types is constructed class E oscillators. The principles of operation and characteristics of some new schemes of class E oscillators and their parameters are considered. The trends in the development of class E generators are determined, the main of which is the design of generators for operation in radio engineering systems and matching their parameters with the needs of such systems, as well as in systems of power (industrial) electronics, wireless energy transmission, biomedical and information systems. This is done in accordance with the trend of increasing the oscillator signal parameters while maintaining high efficiency. The variety of power levels, frequencies, and type of performance of class E oscillators is preserved and expanded, in the form of integrated circuits, which allows increasing the parameters of transmitters, sensors, and systems of compatible energy and information transmission.