E.A. Ishchenko1, V.V. Negrobov2, Yu.G. Pasternak3, V.A. Pendyurin4, S.M. Fedorov5

1–3,5 Voronezh State Technical University (Voronezh, Russia)

2 Joint Stock Company "Scientific Design and Technology Bureau "Ferrite"(Voronezh, Russia)

3,4 Joint Stock Company Scientific and Production Enterprise "Automated Communication Systems"(Voronezh, Russia)

1 kursk1998@yandex.ru, 2 negrobov_VV@mail.ru, 3 pasternakyg@mail.ru, 4 pva777777@yandex.ru, 5 fedorov_sm@mail.ru

Previously, a number of works described and investigated methods to increase the accuracy of determining the direction to the source of radio emission or even the formation of additional channels for receiving signals by using methods of forming "virtual" antenna arrays (VAR). The advantages of the methods under consideration were their invariance to the operating conditions. The initial data were only the geometry of the actual antenna array (RAR) and the signals taken from the loads of the elements of this antenna array.

The article examines the influence of distortions in the structure of the electromagnetic field near a mobile phone caused by the presence of a user's hand in close proximity to the antenna system of a mobile phone on the quality of determining the direction to the source of radio emission using methods of forming "virtual" antenna arrays. Two methods of forming "virtual" antenna arrays are considered: based on the use of auxiliary point sources of the field, as well as a method based on the search for a quasi-solution. It is noted that distortions of the phase structure of the electromagnetic field in the locations of the elements of the antenna system of a mobile phone can significantly reduce the beneficial effect of using methods for forming "virtual" antenna arrays, which leads to an increase in errors in determining the direction to the source of radio emission.

The article presents the frequency dependences of bearings at different radii for virtual and real antenna arrays, the dependences of absolute bearing errors, as well as the phase values of the electric field component on a circle of different radius. Based on all the studies conducted, it can be concluded that the described methods are promising and the need for further research in order to find optimal values of the initial conditions necessary to solve the problem of choosing the number of auxiliary sources, as well as to minimize the objective function.

One of the key areas of application of the results obtained are modern radio engineering systems, which are necessary to improve hardware and software designed for receiving and processing ultra-wideband signals. These include military and special purpose systems, such as radar, radio direction finding, radio navigation, communications and telecommunications, as well as civilian portable telecommunications equipment (mobile phones, Internet access radio modems, personal computers).

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