Time‐modulated multibeam steered antenna array synthesis with optimally designed switching sequence

Abstract

Summary Steering the radiation pattern of an antenna array towards the desired spatial angle is beneficial for modern‐age communication systems. The generation of multiple steered patterns by enhancing the first‐order harmonics of a time‐modulated antenna array (TMAA) with controlled radiation features is proposed in this paper. Suitable switching sequences are designed to realize an efficient electronic beam steering with these simultaneously generated narrow directional beam patterns. TMAAs are considered the time‐domain counterparts of phased arrays where high‐speed switches are used to achieve a weighted response by periodically modulating the array elements instead of attenuators or phase shifters. This periodic modulation inherently produces spurious harmonic patterns generally considered as power loss in unintended directions. The beam steering aimed in this paper is accomplished by exploiting the first‐order harmonic patterns in some specific directions keeping the fundamental pattern unaltered. The intended first positive and first negative harmonic components of the TMAA are utilized as steered multibeam patterns, whereas all the remaining harmonic components are suppressed to improve the efficiency of the array. To achieve this, suitable switching sequences are designed by optimizing the ON‐time duration and switching intervals of the elements with a wavelet mutation‐based particle swarm optimization (PSOWM). 16‐element linear TMAA is used to generate the desired patterns with low sidelobe levels (SLLs) for enhanced performance. Numerical results obtained for spatially independent steered patterns are presented and compared with the state‐of‐the‐art literature results.

Phase center motion based time modulated arrays with preprocessed time schemes for selective harmonic beamforming in B5G communication systems

“…Furthermore, simultaneously lowered SLL and higher-order SBLs have been achieved lately with suitably designed time schemes. [18][19][20] The other research dimension is to exploit the unwanted harmonic patterns, for possible alternate solutions such as harmonic beamforming, 21,22 bidirectional beamforming, [23][24][25] beam scanning, 26,27 beam steering, [28][29][30] multibeam patterns, [31][32][33] direction finding, 34,35 direction of arrival estimation 36,37 and so forth. To explore it further, the investigation of these harmonic patterns is necessary.…”

Power pattern synthesis of a moving phase center time modulated antenna array using symmetrically and asymmetrically positioned time schemes

“…28 An alternatively radiating sumdifference pattern has been discussed with adjustable phase distributions through optimized switching schemes. 29,30 The flexibilities of the harmonic components have come up with cutting-edge applications suitable for multibeam steered patterns, [31][32][33] null pattern synthesis, 34 beam shaping, 35 element failure and detection, 36 radar applications, 37,38 and so on. These applications have further established the diversities and multifunctional capabilities of TMAs.…”

Mutual coupling compensation of linear antenna array using evolutionary optimization technique

“…Antenna arrays are preferred as they allow one to control the beam by varying different parameters. This can be used in applications like the direction of arrival (DoA), 4 beam steering, 5 and pattern synthesis in an antenna array 6 . The energy radiated is distributed among various sidelobes in an antenna array, which reduces the antenna array performance.…”