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Abstract-This study has proposed an adaptive beamformer for pattern nulling of Uniformly Spaced Linear Array (ULA) antennas for interference suppression. This beamformer has been developed based on controlling the complex weight (both the phase and the amplitude) of each array element as pattern nulling and Bat algorithm (BA) as a global optimization approach. So as to verify the proposal, a number of scenarios of ULA pattern with pre-set nulls have been conducted and compared with those of accelerated particle swarm optimization (APSO). As a result, the proposed beamformer has demonstrated the capability to place precisely single, multiple, and broad nulls at arbitrary interference directions, suppress sidelobes, and maintain a predefined main lobe. Moreover, the beamformer shows faster convergence and higher efficiency regarding null steering in pattern synthesis, as compared with an APSO-based beamformer.

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<span>This paper proposes an effective beamformer for uniform linear arrays of half-wave dipole antennas based on binary bat algorithm (BBA) by controlling complex weights (both amplitudes and phases) excited at elements in an array. The proposed beamformer can impose adaptive nulls at interferences without knowing directions in the sidelobe region by minimizing the total output power of an array, whereas the main lobe and sidelobe levels are maintained. To demonstrate this capability, the proposal will be evaluated in several scenarios, compared to a beamformer based on binary particle swarm optimization (BPSO).</span>