TMLAA for Automatic Harmonic Beam Steering Toward User-Defined Direction Using Black Hole Mechanics Optimization

Automatic electronic beam steering of the harmonic beam pattern of the time-modulated linear antenna array (TMLAA) towards the user-defined Direction of Arrival (DOA) is proposed in this work. Black Hole Mechanics Optimization (BHMO) is applied for the first time in harmonic beam steering in TMLAA. A novel and unique fitness evaluation function is designed to steer the main beam of the harmonic radiation pattern towards any given user-defined DOA in an elevation plane ranging from −70° to +70°. The harmonics or sidebands generated due to time-modulation are used to steer the beam into either direction from the fundamental beam simultaneously. To illustrate the asserted idea, a broadside array of 16-element TMLAA with uniform current excitation amplitudes and uniform inter-element spacing is considered with the optimized ON-OFF switching sequences. The designed fitness function (FF) is optimized using the BHMO algorithm to obtain optimal switching of the ON-OFF time sequence. The statistical analysis and results demonstrate the effectiveness of this approach, which shows the steering capabilities of the harmonic beam of any harmonic number. An array of 16-element TMLAA is considered to validate the proposed work. The simulation results show that the first positive and negative harmonic are steered at user-defined DOA. The Bit Error Rate (BER) over an additive white Gaussian noise (AWGN) channel is computed in this context from the numerical results obtained from the far-field beams of a 16-element TMLAA for (0, −30°, 30°) in order to highlight the suitability of the suggested TMLA for digital communication purposes, specifically for digital phase shift keying (PSK) modulation.