E.A. Ishchenko1, Yu.G. Pasternak2, V.A. Pendyurin3, S.M. Fedorov4

1,2,4 Voronezh State Technical University (Voronezh, Russia)

2,3 JSC NPP "Automated Communication Systems" (Voronezh, Russia)

The task of improving the accuracy of direction finding is in demand in modern communication systems. Errors in determining the direction of arrival of electromagnetic waves are caused by many factors: the carrier body, soils, inhomogeneities of the medium, and others. To solve these problems, many methods are used, one of which is the approximation of electromagnetic waves with the formation of a virtual antenna array (VAA). The possibility of using virtual antenna arrays is considered in many works.

The formation of virtual antenna arrays is based on the mathematical processing of the field characteristics that the direction finding system will measure. The approximation of electromagnetic waves during the formation of a virtual antenna array was carried out on the basis of two methods: the Hankel function, which acts as a solution to the fundamental Helmholtz equations; magnetic di-fields obtained on the basis of Maxwell's equations in integral form. When forming virtual antenna arrays, real direction finding complexes were used, which were placed on a mobile platform. To form a virtual antenna array based on the Hankel function, an annular antenna array made of conical antenna elements that measure the characteristics of the incident electromagnetic field was used. To form magnetic dipoles, four vector antenna elements were used, which were used to measure the characteristics of electromagnetic waves.

The obtained modeling results show that both methods of forming virtual antenna arrays provide an increase in the accuracy of direction finding in comparison with real antenna arrays.

The use of a virtual antenna array formed on the basis of the Hankel function allows for a wider range of operating frequencies, while maintaining higher accuracy compared to magnetic dipoles, but when forming such a virtual antenna array, it is necessary to install a large direction finder, which takes up a lot of space; at the same time, the use of magnetic dipoles allows you to use four small vector antenna elements, which provides greater flexibility in choosing the location of the direction finder.

The article presents mathematical algorithms for the formation of virtual antenna arrays, models studied, bearing patterns and statistical indicators of direction finding when using real and virtual antenna arrays.

The research was carried out at the expense of the grant of the Russian Science Foundation No. 19-79-109, https://rscf.ru/project/19-79-10109/.

Ishchenko E.A., Pasternak Yu.G., Pendyurin V.A., Fedorov S.M. Comparison of the efficiency of forming virtual antenna arrays based on the Hankel function and magnetic dipoles for geometrically complex purposes. Radiotekhnika. 2023. V. 87. № 2. P. 163−171. DOI: https://doi.org/10.18127/j00338486-202302-19 (In Russian)

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