The purpose of this work is to obtain an expression for the discriminative characteristic of the spin wave phase comparator, which is the dependence of the amplitude of the output voltage on the phase difference of the exciting microwave oscillations. This comparator is based on an antiferromagnetic film and three microstrip antennas, two of which receive microwave signals, the phases of which need to be compared, and the output voltage is removed from the third. In addition, this paper examines the behavior of the discriminative characteristic for various positions of the receiving antenna.

Methods. To describe an antiferromagnetic waveguide, an equivalent electrical circuit based on concentrated elements was compiled. The radio engineering model was considered in the form of active and reactive resistances of spin wave excitation and reception antennas, as well as active and reactive resistances characterizing the propagation of spin waves in an antiferromagnetic film. The components of the magnetic susceptibility tensor of an antiferromagnet are derived from the Landau-Lifshitz-Hilbert equations,
which made it possible to describe the relationship between the electric and magnetic systems. The theoretical results were confirmed using micromagnetic modeling.

Results. The principle of operation of a spin wave phase comparator based on an antiferromagnetic film is described. Using an equivalent electrical circuit, the main characteristic of the comparator is obtained - the dependence of the amplitude of the output voltage at the receiving antenna on the phase difference of the exciting microwave signals. Also, the dependence of the amplitude of the output voltage on the position of the receiving antenna is constructed. Micromagnetic modeling was carried out to verify the theoretically obtained results.

Conclusion. In this paper, an expression is obtained for the discriminatory characteristic of an antiferromagnetic film-based comparator with an arbitrary location of the receiving antenna. It is shown that the discriminative characteristic depends on the spatial location of the receiving antenna. The highest efficiency of the comparator is achieved if the detector is located in the middle between the exciting antennas.