volume | PIER Journals

Abstract

In this paper, the synthesis of sparse time-modulated linear arrays with minimum number of elements and controlled harmonic radiations is investigated. The proposed iterative approach based on a particle swarm optimization is aimed at finding the array configuration with the minimum number of elements and the optimal pulse sequence that affords a beam pattern with the same features of a reference one also limiting the amount of sideband radiations under a specific threshold. A set of representative numerical examples are discussed to assess the effectiveness and the reliability of the proposed approach.

1. Shanks, H. E. and R. W. Bickmore, "Four-dimensional electromagnetic radiators," Canad. J. Phys., Vol. 37, 263-275, 1959.
doi:10.1139/p59-031 Google Scholar

2. Labate, M. G., A. Buonanno, M. D'Urso, G. Calzolaio, A. Vacca, L. Zeni, G. Leone, and G. Roccardo, "Photoconductive switches for radar systems exploiting time domain," Proc. 5th European Conference on Antennas and Propagation (EuCAP 2011), 850-852, Apr. 2011. Google Scholar

3. Kummer, W. H., A. T. Villeneuve, T. S. Fong, and F. G. Terrio, "Ultra-low sidelobes from time-modulated arrays," IEEE Trans. Antennas Propag., Vol. 11, No. 6, 633-639, 1963.
doi:10.1109/TAP.1963.1138102 Google Scholar

4. Yang, S., Y. B. Gan, and A. Qing, "Sideband suppression in time-modulated linear arrays by the differential evolution algorithm," IEEE Antennas Wireless Propag. Lett., Vol. 1, No. 1, 173-175, 2002.
doi:10.1109/LAWP.2002.807789 Google Scholar

5. Yang, S., Y. B. Gan, and P. K. Tan, "Comparative study of low sidelobe time modulated linear arrays with different time schemes," Journal of Electromagnetic Waves and Applications , Vol. 18, No. 11, 1443-1458, 2004.
doi:10.1163/1569393042954910 Google Scholar

6. Mandal, S. K., G. K. Mahanti, and R. Ghatak, "Differential evolution algorithm for optimizing the conflicting parameters in time-modulated linear array antennas," Progress In Electromagnetics Research B, Vol. 51, 101-118, 2013. Google Scholar

7. Zhu, Q., S. Yang, R. Yao, and Z. Nie, "Design of a low sidelobe 4D planar array including mutual coupling," Progress In Electromagnetics Research M, Vol. 31, 103-116, 2013. Google Scholar

8. Fondevila, J., J. C. Bregains, F. Ares, and E. Moreno, "Optimizing uniformly excited linear arrays through time modulation," IEEE Antennas Wireless Propag. Lett., Vol. 3, No. 1, 298-301, 2004.
doi:10.1109/LAWP.2004.838833 Google Scholar

9. Poli, L., P. Rocca, L. Manica, and A. Massa, "Handling sideband radiations in time-modulated arrays through particle swarm optimization," IEEE Trans. Antennas Propag., Vol. 58, No. 4, 1408-1411, Apr. 2010.
doi:10.1109/TAP.2010.2041165 Google Scholar

10. Poli, L., P. Rocca, L. Manica, and A. Massa, "Time modulated planar arrays --- Analysis and optimisation of the sideband radiations," IET Microw. Antennas Propag., Vol. 4, No. 9, 1165-1171, 2010.
doi:10.1049/iet-map.2009.0379 Google Scholar

11. Rocca, P., L. Poli, G. Oliveri, and A. Massa, "Synthesis of time-modulated planar array with controlled harmonic radiations," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 4, 827-838, 2010.
doi:10.1163/156939310791036304 Google Scholar

12. Poli, L., P. Rocca, L. Manica, and A. Massa, "Pattern synthesis in time-modulated linear arrays through pulse shifting," IET Microw. Antennas Propag., Vol. 4, No. 9, 1157-1164, 2010.
doi:10.1049/iet-map.2009.0042 Google Scholar

13. Yang, S., Y. B. Gan, A. Qing, and P. K. Tan, "Design of a uniform amplitude time modulated linear array with optimized time sequences," IEEE Trans. Antennas Propag., Vol. 53, No. 7, 2337-2339, Jul. 2005.
doi:10.1109/TAP.2005.850765 Google Scholar

14. Zhu, Q., S. Yang, L. Zheng, and Z. Nie, "Design of a low sidelobe time modulated linear array with uniform amplitude and sub-sectional optimized time-steps," IEEE Trans. Antennas Propag. , Vol. 60, No. 9, 4436-4439, Sep. 2012.
doi:10.1109/TAP.2012.2207082 Google Scholar

15. Bekele, E. T., L. Poli, M. D'Urso, P. Rocca, and A. Massa, "Pulse-shaping strategy for time modulated arrays --- Analysis and design," IEEE Trans. Antennas Propag., Vol. 61, No. 7, 3525-3537, Jul. 2013.
doi:10.1109/TAP.2013.2256096 Google Scholar

16. Tong, Y. and A. Tennant, "Sideband level suppression in time-modulated linear arrays using modified switching sequences and fixed bandwidth elements," Elect. Lett., Vol. 48, No. 1, 10-11, Jan. 2012.
doi:10.1049/el.2011.2378 Google Scholar

17. Poli, L., P. Rocca, and A. Massa, "Sideband radiation reduction exploiting pattern multiplication in directive time-modulated linear arrays," IET Microw. Antennas Propag., Vol. 6, No. 2, 214-214, 2012.
doi:10.1049/iet-map.2011.0159 Google Scholar

18. Aksoy, E. and E. Afacan, "Thinned nonuniform amplitude time-modulated linear arrays," IEEE Antennas Wireless Propag. Lett. , Vol. 9, 514-517, May 2010.
doi:10.1109/LAWP.2010.2051312 Google Scholar

19. Chen, Y., S. Yang, and Z. Nie, "Synthesis of satellite footprint patterns from time-modulated planar arrays with very low dynamic range ratios," Int. J. Numer. Model., Vol. 21, 493-506, 2008.
doi:10.1002/jnm.684 Google Scholar

20. Rocca, P., L. Manica, L. Poli, and A. Massa, "Synthesis of compromise sum-difference arrays through time-modulation," IET Radar Sonar Navig., Vol. 3, No. 6, 630-637, Nov. 2009.
doi:10.1049/iet-rsn.2009.0058 Google Scholar

Dr. Paolo Rocca

Dr. Michele D‘Urso

Dr. Lorenzo Poli