In this paper, the space-and-time structure of the output signal of the antenna array (AA) of a chirp pulse radar is investigated in dependence on the frequency sweep range of the probe signal. Expressions are derived for calculating the output signals of the AA of a chirp pulse radar after optimal filtering in the case of beamforming using phase shifters and/or time-delay lines. Distortions of the space-time power pattern pertaining to the phase scanning method are analyzed in dependence on the frequency chirp range and scan angle. It is shown that these distortions are similar to the effects observed in the case of using taper windows for sidelobe suppression in the time and space (angular) domains. Based on the results obtained an applicability condition is suggested for the phase scanning in AAs of chirp pulse radars. It is shown that minor violations of this condition result in decreasing the amplitude and broadening of the main lobe and sidelobes in the AA space-time power pattern. In the case of strong violations of the applicability condition for the phase scanning the sidelobes of the angular directional pattern degrade, merging with the main one into a single quite broad maximum. The considered effects lead to deterioration of the range and azimuth resolution capabilities of radars and should be taken into account when selecting the taper window parameters.
2. Swords, S. S., Technical History of the Beginnings of Radar, IEE/Peter Peregrinus, London, 1986.
3. Blanchard, Y., G. Galati, and P. Van Genderen, "The cavity magnetron: Not just a British invention," IEEE Antennas and Propagation Magazine, Vol. 55, No. 5, 244-254, 2013.
4. De Size, L. K. and J. F. Ramsay, "Reflecting systems," Microwave Scanning Antennas, Vol. 1, Apertures, Ch. 2, 107-213, R. C. Hansen, ed., Academic Press, New York, London, 1964.
5. Cooley, M. E. and D. Davis, "Reflector antennas," Radar Handbook, 12.1-12.43, M. I. Skolnik, ed., McGraw-Hill Companies, New York, Chicago, San Francisco et al., 2008.
6. Frank, J. and J. D. Richards, "Phased array radar antennas," Radar Handbook, 13.1-13.74, M. I. Skolnik, ed., McGraw-Hill Companies, New York, Chicago, San Francisco et al., 2008.
7. Sturdivant, R. and M. Harris, Transmit Receive Modules for Radar and Communication Systems, Artech House, Inc., Boston, London, 2016.
8. Klemm, R., U. Nickel, C. Gierull, P. Lombardo, H. Griffiths, W. Koch, and eds., "Novel Radar Techniques and Applications, Vol. 2, Waveform Diversity and Cognitive Radar, and Target Tracking and Data Fusion," The Institution of Engineering and Technology, 2018.
9. Jeffrey, T. W., Phased-Array Radar Design: Application of Radar Fundamentals, SciTech Publishing, Inc., 2009.
10. BCC Research, 2018.5 Key Trends in Radar Technology, Radar Manufacturing: Global Markets to 2022, BCC Research Report IAS052A [online], [viewed 15.11.2020], Available from: http://blog.bccresearch.com/5-key-trends-in-radar-technology.
11. Liu, M., L. Zou, and X. Wang, "Practical beamforming technologies for wideband digital array radar," Progress In Electromagnetics Research Letters, Vol. 86, 145-151, 2019.
12. Jun, W., C. Duo-Duo, and Y. Fan, "Aperture effect influence and analysis of wideband phased array radar," Procedia Engineering, Vol. 29, 1298-1303, 2012.
13. Ajioka, J. S., "Frequency scan antennas," Antenna Engineering Handbook, Ch. 19, 19.1-19.30, R. C. Johnson (ed.), Mc-Graw Hill, Inc., New York, Louis, San Francisco, etc., 1993.
14. Mailloux, R. J., Phased Array Antenna Handbook, Artech House, Inc., Boston, London, 2005.
15. Cook, C. E. and M. Bernfeld, Radar Signals: An Introduction to Theory and Application, Academic Press, New York, London, 1967.
16. Maurice, R. D. A., Convolution and Fourier Transforms for Communications Engineers, Pentech Press Ltd., London, 1976.
17. Snieder, R., A Guided Tour of Mathematical Methods for the Physical Sciences, Cambridge University Press, Cambridge, 2009.
18. Galushko, V. G., "On application of taper windows for sidelobe suppression in LFM pulse compression," Progress In Electromagnetics Research C, Vol. 107, 259-271, 2021.
19. Doerry, A. W., Catalog of Window Taper Functions for Sidelobe Control, Technical ReportSAND2017-4042, Sandia National Labs., Albuquerque, New Mexico and Livermore, California, USA, 2017.