The monopulse ratio slope close to the blinding angles of phased array antenna

Аuthors

Anyutin N. V.^*, Mokrov I. V., Semenov A. A.

,

*e-mail: anyutinnv@mail.ru

Abstract

In the article the phenomenon of increasing systematic measurement error of target angular coordinates by monopulse radar systems near the blinding angles of a phased array antenna is described. To explain this phenomenon, a method for calculating phased array antenna scanning patterns using the multiplication theorem and subsequent calculation of the directivity is proposed. Within this approach, the phenomenon of phased array antenna blinding is explained by the outflow of a portion of the radiated power into a wide diffraction lobe in the direction of the array plane. The diffraction maxima of the sum and difference channel radiation patterns do not intersect the boundary of the imaginary angle region simultaneously. This leads to misaligning widths and depths of the nulls in their scanning patterns. A change in the gain of sum and difference channels of a monopulse radar system entails a change in the slope of the linear area of monopulse ratio, which is not taken into account in the measurement model.
Experimental studies were conducted to examine the change in the monopulse ratio slope near the blinding angles of a 256-element phased array antenna. The calculation of the directivity based on the measured cross-section of 8 radiation patterns of the sum channel coincided with the scanning pattern measured in the same cross-section with an error less than ±0.5 dB. The monopulse ratio slope calculated based on the measured cross-sections of the radiation patterns of the sum and difference channels increases by 20 % before the blinding angle and decreases by 15 % within it. The monopulse ratio slope calculated using the proposed method for calculating scanning patterns is a maximum of 19 % higher and a minimum of 16 % lower relative to the value normal to the plane of the phased array antenna. Thus, the proposed method for calculating scanning patterns made it possible to describe the phenomenon of increasing systematic measurement error of target angular coordinates by monopulse radar systems near the blinding angles of a phased array antenna.

Keywords:

monopulse radar; monopulse ratio; phased array antenna; radiation pattern; scanning pattern

References

1. Suchkov A. V. Trudy MAI: electron. zhurn, 2016. no. 86. Available at: https://trudymai.ru/published.php?ID=66408
2. Shmachilin P. A., Shumilov T. Y. Trudy MAI: electron. zhurn, 2019. no. 109. Available at: https://trudymai.ru/published.php?ID=111382 DOI 10.34759/trd-2019-109-12
3. Oreshkin V. I., Meleshin Y. M., Tsvetkov V. K. Trudy MAI: electron. zhurn, 2021. no. 120. Available at: https://trudymai.ru/published.php?ID=161424 DOI 10.34759/trd-2021-120-10
4. Sherman S. M., Barton D. K. Monopulse principles and techniques.  Artech House, 2011.
5. Nickel U. Overview of generalized monopulse estimation IEEE Aerospace and Electronic Systems Magazine, 2006, vol. 21, no. 6, pp. 27-56. DOI: 10.1109/MAES.2006.1662039
6. Dunn J. H., Howard D. D. The effects of automatic gain control performance on the tracking accuracy of monopulse radar systems Proceedings of the IRE, 1959, vol. 47, no. 3, pp. 430-435. DOI: 10.1109/JRPROC.1959.287179
7. Barton D. K. Low-angle radar tracking Proceedings of the IEEE, 1974, vol. 62, no. 6, pp. 687-704. DOI: 10.1109/PROC.1974.9509
8. Seifer A. D. Monopulse-radar angle tracking in noise or noise jamming IEEE Transactions on Aerospace and Electronic Systems, 2002, vol. 28, no. 3, pp. 622-638. DOI: 10.1109/7.256285
9. Meleshin Y. M. Trudy MAI: electron. zhurn, 2024. no. 135. Available at: https://trudymai.ru/published.php?ID=179687
10. Hansen R. C. Phased Array Antennas. 2009.
11. Yastrebtsova O. I. Trudy MAI: electron. zhurn, 2017. no. 97. Available at: https://trudymai.ru/published.php?ID=87318
12. Hannan P. The element-gain paradox for a phased-array antenna IEEE Transactions on Antennas and Propagation, 1964, vol. 12, no. 4, pp. 423-433. DOI: 10.1109/TAP.1964.1138237
13. Galindo V., Wu C. Integral equations and variational expressions for arbitrary scanning of regular infinite arrays IEEE Transactions on Antennas and Propagation, 1966, vol. 14, no. 3, pp. 392-394. DOI: 10.1109/TAP.1966.1138686
14. Kelley D. F., Stutzman W. L. Array antenna pattern modeling methods that include mutual coupling effects IEEE Transactions on antennas and propagation, 1993, vol. 41, no. 12, pp. 1625-1632. DOI: 10.1109/8.273305
15. Warnick K. F., Davidson D. B., Buck D. Embedded element pattern loading condition transformations for phased array modeling IEEE Transactions on Antennas and Propagation, 2020, vol. 69, no. 3, pp. 1769-1774. DOI: 10.1109/TAP.2020.3027593
16. Marinović T. et al. Comparison of CBFM-enhanced iterative methods for MoM-based finite antenna array analysis IEEE Transactions on Antennas and Propagation, 2021, vol. 70, no. 5, pp. 3538-3548. DOI: 10.1109/TAP.2021.3137484
17. Vinichenko YU. P., Tumanskaya A. E. Antenny, 2008, no. 5, pp. 16-21.
18. Bhattacharyya A. K. An accurate model for finite array patterns based on Floquet modal theory IEEE Transactions on Antennas and Propagation, 2015, vol. 63, no. 3, pp. 1040-1047. DOI: 10.1109/TAP.2015.2389249
19. Vosoogh A., Kildal P. S. Simple Formula for Aperture Efficiency Reduction Due to Grating Lobes in Planar Phased Arrays IEEE Transactions on Antennas and Propagation, 2016, no. 64, vol. 6, pp. 2263-2269. DOI: 10.1109/TAP.2016.2551259
20. Isakov M. A. et al. Vestnik Koncerna VKO “Almaz-Antey”, 2023, no. 4, pp. 55–63. DOI: 10.1109/TAP.2021.3137484

Download