ON THE ISSUE OF DETERMINING PHASE SHIFTS IN THE MIXER

Abstract

The aim of the study is to solve the problem of the influence of the nonlinearity of phase shifts of
harmonics during frequency multiplication on the measurement results of absolute phase shifts occurring
in mixers and errors in various measurement methods of these shifts in the mixer during heterodyne frequency
conversion of the input ultrahigh frequency (microwave) signal. Since the signal at the input of the
microwave mixer and the intermediate frequency signal at its output lie in different frequency ranges, it is
impossible by traditional methods to measure the phase shift introduced by the nonlinear element of the
mixer into the intermediate frequency signal during the heterodyne frequency conversion of the input microwave
signal. The problem that we have considered in this study is to identify the measurement error of
absolute 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 its
accounting and compensation are important tasks in radio engineering and communications. This scientific
article demonstrates the important inequality of the phase shifts of harmonics multiplied by the phase
shift of the multiplied signal used in the measurement methods of absolute phase shifts of mixers. We also
proposed 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 study
are of great importance for accurate measurements in radio engineering and communications. The proposed
method, devoid of these errors, can significantly increase the accuracy of measurements of absolute
phase shifts of mixers with heterodyne frequency conversion. This innovative solution allows you to take
into account the nonlinearity of the mixing diode and provide accurate measurements, which can be very
useful when creating devices capable of measuring the phase shift of the microwave mixer under test and
vector voltmeters based on programmable logic integrated circuits (FPGAs).