One of the primary features of time-modulated arrays (TMAs) is their ability to adapt their harmonic patterns to exploit the angular diversity of multipath wireless channels. In such a case, the TMA excitations must provide an adequate level of harmonic windowing in order to safeguard both the antenna efficiency and the signal-to-noise ratio at reception. In this work, we propose to time-modulate the array excitations with periodic sum-of-weighted-cosine (SWC) pulses rather than with the periodic rectangular pulses corresponding to the  on–off  switches of conventional TMAs. We show that how the larger flexibility of the SWC pulses allows for a more versatile design of the TMA harmonic radiation patterns without penalizing the array gain for each exploited harmonic.
['Roberto Maneiro-Catoira', 'Julio C. Bregáins', 'José Antonio García-Naya', 'Luis Castedo']
Enhanced Time-Modulated Arrays for Harmonic Beamforming