Radiophotonic methods and means for the resolution increase of a continuous-wave radar with an FBG discriminator

During the development of a radiophotonic systems for instantaneous microwave frequencies measurement, ever higher requirements are placed on their range, accuracy, and resolution, which can only be satisfied by the creation of a new devices and operating principles. Three types of analysis of frequency components after modulation are possible: analysis of each component separately (differential analysis), analysis of the envelope of each two-frequency pair (integral-derivative analysis), and analysis of all components (integral analysis). All these methods are realizable and correspond to one-, two-, and polyharmonic FBG probing using a limited number of optical band-pass filters. Based on the results of a comparative analysis, it was shown that the problem of the resolution increase of the instantaneous frequency measurement of microwave signals in symmetrical circuits on selective elements can be solved by transferring the frequency components of the measured signal to the middle of the linear section of the FBG; using radiophotonic multiplication and using polyharmonic transformation of the measured frequency on TAPM. Among the advantages of such solutions, the possibility of the resolution increase of the frequency measurement of microwave signals lies in low frequencies measurement in the linear section of the FBG when transferring the frequency components of the measured signal, a multiple decrease in the measurement error by a factor equal to the number of multiplication stages for radiophotonic multiplication and a multiple of the number of harmonics used for the method of polyharmonic transformation.