PHOTONIC SYSTEMS FOR MEASURING INSTANTANEOUS FREQUENCY OF MICROWAVE SIGNALS BASED ON FREQUENCY DISCRIMINATORS – FIBER BRAGG GRATINGS. REVIEW

Abstract

Photonic receivers for measuring the instantaneous frequency of microwave signals are devices used to measure the instantaneous frequency and amplitude of one or more microwave signals in the optical range for radar systems. In the development of such devices, increasingly high requirements are imposed on the frequency range, accuracy and resolution of measurements of the instantaneous frequency of microwave signals, which are met by the creation of new devices and principles of their operation. For further development in this area, it is necessary to summarize the experience gained in the development of devices based on frequency discriminators, including promising ones - the integral type. This article provides an overview of approaches that use frequency discriminators based on fiber Bragg gratings. The principles of their operation, as well as the associated advantages, disadvantages and existing solutions to the identified problems are considered in detail.