ON THE ISSUE OF DETERMINING PHASE SHIFTS IN THE MIXER

The aim of the study is to solve the problem of the influence of the nonlinearity of phase shifts ofharmonics during frequency multiplication on the measurement results of absolute phase shifts occurringin mixers and errors in various measurement methods of these shifts in the mixer during heterodyne frequencyconversion of the input ultrahigh frequency (microwave) signal. Since the signal at the input of themicrowave mixer and the intermediate frequency signal at its output lie in different frequency ranges, it isimpossible by traditional methods to measure the phase shift introduced by the nonlinear element of themixer into the intermediate frequency signal during the heterodyne frequency conversion of the input microwavesignal. The problem that we have considered in this study is to identify the measurement error ofabsolute phase shifts that occur in a mixing diode during heterodyne frequency conversion due to its nonlinearity.This error can have a significant impact on the accuracy of measurements, and therefore itsaccounting and compensation are important tasks in radio engineering and communications. This scientificarticle demonstrates the important inequality of the phase shifts of harmonics multiplied by the phaseshift of the multiplied signal used in the measurement methods of absolute phase shifts of mixers. We alsoproposed an innovative method devoid of these measurement errors, which allows us to take into account the nonlinearity of the mixing diode and provide more accurate measurements. The results of this studyare of great importance for accurate measurements in radio engineering and communications. The proposedmethod, devoid of these errors, can significantly increase the accuracy of measurements of absolutephase shifts of mixers with heterodyne frequency conversion. This innovative solution allows you to takeinto account the nonlinearity of the mixing diode and provide accurate measurements, which can be veryuseful when creating devices capable of measuring the phase shift of the microwave mixer under test andvector voltmeters based on programmable logic integrated circuits (FPGAs).