Instantaneous microwave frequency measurement with monitoring of system temperature

Abstract

This paper presents a new two-frequency method for the instantaneous frequency and amplitude measurement of unknown microwave signal. Using the specific interaction of two-frequency radiation with fiber Bragg grating (FBG) in first version and FBG with phase π-shift in second allowed us to obtain measuring characteristics, that are independent of the energy fluctuations of the optical carrier and the microwave signal. Frequency measurement occurs in two ranges: 3-30 GHz in FBG reflection band, and in second version 0,3-3 GHz in the FBG pass band. Additional circuit for spectral characteristics monitoring of the used elements are organized to reduce measurement inaccuracy caused by their temperature instability.