Electronic Beam Steering in Timed Antenna Array by Controlling the Harmonic Patterns with Optimally Derived Pulse-Shifted Switching Sequence

An efficient electronic beam steering method in timed antenna array is proposed in this paper by controlling only the high-speed switches connected with the radiating elements of the array. The timed antenna arrays have an extra dimension—‘time’ to control the array radiation pattern compared to traditional antenna arrays. The simple on–off sequence of these arrays inherently generates undesired harmonic patterns along with the desired pattern. These unwanted and spatially individual patterns generated at lower-order harmonic frequencies are exploited in this paper with appropriate on–off sequence to generate multiple steered patterns toward preselected directions. The sidelobes of all the desired patterns are reduced, and the unwanted harmonics are suppressed. To achieve the desired objectives, unique pulse-shifted on–off sequences are derived with a modified differential evolution algorithm by implementing an efficient wavelet-based mutation operation. A linear arrangement of timed array with ten isotropic elements is considered to exhibit the potentialities of the proposed approach.