eprintid: 459 rev_number: 7 eprint_status: archive userid: 5 dir: disk0/00/00/04/59 datestamp: 2011-04-22 lastmod: 2013-07-01 09:20:46 status_changed: 2013-07-01 09:20:46 type: techreport metadata_visibility: show item_issues_count: 0 creators_name: Poli, Lorenzo creators_name: Rocca, Paolo creators_name: Manica, Luca creators_name: Massa, Adnrea title: Pattern synthesis in time-modulated linear arrays through pulse shifting ispublished: pub subjects: TU full_text_status: public keywords: particle swarm optimisation , pattern synthesis , sideband radiations , time-modulated elements , time-modulated linear array antenna abstract: In this study, an innovative approach for the synthesis of time-modulated linear array (TMLA) antennas is presented. The switch-on instants of the time-modulated elements are taken into account as additional degrees of freedom to optimise the array pattern. Towards this end, a technique based on a particle swarm optimisation is proposed to fully exploit the dependence of the sideband radiations (SR) on the shift of the time pulses. A set of representative results are reported to assess the effectiveness of the proposed approach as well as its flexibility. "This paper is a postprint of a paper submitted to and accepted for publication in IET Microwaves, Antennas & Propagation and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital Library" date: 2011-01 date_type: published institution: University of Trento department: informaticat refereed: TRUE referencetext: [1] Kummer, W. H., Villeneuve, A. T., Fong, T. S., and Terrio, F. G.: "Ultra-low sidelobesfrom time-modulated arrays", IEEE Trans. Antennas Propag., 1963, 11, (6), pp. 633-639. [2] Shanks, H. E., and Bickmore, R. W.: "Four-dimensional electromagnetic radiators",Canad. J. Phys., 1959, 37, pp. 263-275. [3] Weeks, W. L. "Antenna Engineering"; (New York: McGraw-Hill, 1968). [4] Bickmore, R. W.: "Time versus space in antenna theory"; in Hansen, R. C.: "MicrowaveScanning Antennas", (Ed. Los Altos, CA: Peninsula, 1985), vol. III, ch. 4. [5] Yang, S., Gan, Y. B., and Qing, A.: "Sideband suppression in time-modulated linear arraysby the differential evolution algorithm", IEEE Antennas Wireless Propag. Lett., 2002, 1,pp. 173-175. [6] Yang, S., Gan, Y. B., and Tan, P. K.: "A new technique for power-pattern synthesis in time-modulated linear arrays", IEEE Antennas Wireless Propag. Lett., 2003, 2, pp. 285-287. [7] Yang, S., Gan, Y. B., and Qing, A.: "Moving phase center antenna arrays with optimizedstatic excitations", Microw. Opt. Technol. Lett., 2003, 38, pp. 83-85. [8] Fondevila, J., Brégains, J. C., Ares, F. , and Moreno, E.: "Optimizing uniformly excitedlinear arrays through time modulation";, IEEE Antennas Wireless Propag. Lett., 2004, 3,pp. 298-301. [9] Yang, S., Gan, Y. B., and Tan, P. K.: "Comparative study of low sidelobe time modulatedlinear arrays with different time schemes", JEMWA, 2004, 18, (11), pp. 1443-1458. [10] Yang, S., Gan, Y. B., and Tan, P. K.: "Linear antenna arrays with bidirectional phase centermotion", IEEE Trans. Antennas Propag., 2005, 53, (5), pp. 2337-2339. [11] Yang, S., Gan, Y. B., Qing, A., and Tan, P. K.: "Design of a uniform amplitude timemodulated linear array with optimized time sequences", IEEE Trans. Antennas Propag.,2005, 53, (7), pp. 2337-2339. [12] Fondevila, J., Brégains, J. C., Ares, F., and Moreno, E.: ’Application of time modulation in the synthesis of sum and difference patterns by using linear arrays’, Microw. Opt. Technol. Lett., 2006, 48, pp. 829-832. [13] Tennant A., and Chambers, B.: ’Control of the harmonic radiation patterns of timemodulated antenna arrays’, Proc. 2008 IEEE AP-S International Symp., S. Diego, California, USA, July 5-12, 2008. [14] Brégains, J. C., Fondevila, J., Franceschetti, G., and Ares, F.: ’Signal radiation and power losses of time-modulated arrays’, IEEE Trans. Antennas Propag., 2008, 56, (6), pp. 1799- 1804. [15] Kennedy, J., Eberhart, R. C., and Shi, Y.: ’Swarm Intelligence’ (San Francisco, CA: Morgan Kaufmann, 2001). [16] Robinson, J., and Rahmat-Samii, Y., ’Particle swarm optimization in electromagnetics’, IEEE Trans. Antennas Propag., 2004, 52, (2), pp. 397-407. [17] Dolph, C. L.: ’A current distribution for broadside arrays which optimizes the relationship between beam width and sidelobe level’, Proc. IRE, 1946, 34, pp. 335-348. [18] Donelli, M., Franceschini, G., Martini, A., and Massa, A.: ’An integrated multiscaling strategy based on a particle swarm algorithm for inverse scattering problems’, IEEE Trans. Geosci. Remote Sens., 2006, 44, (2), pp. 298-312. citation: Poli, Lorenzo and Rocca, Paolo and Manica, Luca and Massa, Adnrea (2011) Pattern synthesis in time-modulated linear arrays through pulse shifting. [Technical Report] document_url: http://www.eledia.org/students-reports/459/1/DISI-11-074-R183.pdf