E. S. Artemova – Post-graduate Student, Senior Engineer,

JSC “Concern “Sozvezdie” (Voronezh)

E-mail: artemovaes92@mail.ru

P. V. Novikov – Leading Designer,

JSC “Concern “Sozvezdie” (Voronezh)

E-mail: novikov.p82@mail.ru

M. P. Slichenko – Dr.Sc. (Eng.), Head of Sector,

JSC “Concern “Sozvezdie” (Voronezh)

E-mail: m.p.slichenko@sozvezdie.su

The problem of increasing the detection range of the radio emission source and increasing the size of the radio monitoring zone when placing the detector-direction finder as the target load on the aircraft has been considered. Improving the accuracy of direction finding and resolving power of the detector-direction finder in elevation is provided by the use of a three-dimensional helical antenna array. Antenna elements are located along a helix – a curve in three-dimensional space located on a round cylinder, while the projection onto the plane is a circle. The location along the helix can be both at the same distance from each other (the case of an equidistant helical array), and with a variable vertical step (for example, changing exponentially). The configuration of a helical antenna array with a variable step provides an increase in the curvature of the uncertainty function at the maximum, and therefore, the accuracy and resolution of direction finding in the elevation plane.

The proposed structure of a three-dimensional helical antenna array with a variable step (varying exponentially) in comparison with an equidistant helical antenna array provides improved direction finding accuracy and resolution in elevation. The use of a variablestep helical antenna array in multichannel monopulse direction-finding detectors makes it possible to increase the efficiency of direction finding of radio signal sources by elevation (most significant at angles less than 20 degrees) without increasing the number of antenna elements, radio-receiving channels of a direction-finding detector, azimuth direction-finding sector and the operating frequency range.

Results of calculations for a noninteracting dot helical antenna array and a helical antenna array with a mast with the characteristics gained by results of electrodynamic modelling, are well agreed. It allows to draw a conclusion about possibility of using as a first approximation of a model of dot noninteracting helical antenna array for research of direction finding characteristics of a helical antenna array, at least at comparative researches of helical antenna arrays with various parameters.

The helical antenna array can find wide practical application in complexes and means of radio monitoring with direction finding of sources in azimuth and elevation.

Results of research of the helical antenna array characteristics with other laws of changing a step between elements along a vertical will find reflection in the subsequent publications of authors.

1. Artemov M.L., Afanasyev O.V., Slichenko M.P. Detection and direction finding of radio sources within the framework of the theory of statistical radio engineering. Radioengineering. 2016. № 5. P. 26–40. (in Russian)
2. Artemov M.L., Afanasyev O.V., Slichenko M.P. Methods of statistical radio engineering in the modern solution of radio monitoring problems. Antennas. 2016. № 6. P. 55–62. (in Russian)
3. Vinogradov A.D., Nikitenko E.P. The method of construction and parameters of volumetric antenna arrays of wide-band azimuthelevation radio direction finders with a circular working area. Antennas. 2019. № 3. P. 6–15. (in Russian)
4. Artemov M.L., Afanasyev O.V., Slichenko M.P. Analysis of direction-finding characteristics of an equidistant helical antenna array. Radio communication theory and technology. 2018. № 4. P. 92–99. (in Russian)
5. Patent RU № 2696095. Method for two-dimensional monopulse direction finding of radio emission sources. M.L. Artemov, O.V. Afanasyev, M.P. Slichenko, E.S. Artemova. Publ. 31.07.2019. Bul. № 22. (in Russian)
6. Artemov M.L., Afanasyev O.V., Slichenko M.P. Potential accuracy of joint estimation of azimuth and elevation angle of the direction of arrival of radio waves from sources of radio emission. Antennas. 2018. № 5. P. 38–46. (in Russian)