Quantum‐Approximated Unconventional Sidelobe Canceling Beamformer for Bidirectional Scanning and Sectoral Jamming Mitigation

ABSTRACT The proposed research is aimed to develop an efficient sidelobe canceling beamformer antenna for beam scanning and jamming mitigation in radar using time‐modulation. Beam scanning is directing the antenna radiation patterns toward a specific angular region in the space to locate a particular object or a signal from a specific direction using phased or mechanically scanned antennas. The time‐modulated antenna arrays are unconventional alternatives to phased antennas where the phase deviations between the impinging signals can be controlled through suitable switching ON and OFF time instants of each element in the antenna. The design of a quantum‐approximated optimal time‐modulated beamformer is addressed in this research by aiming for a wide scan coverage of 90° in the broadside. The scanned beams are created by employing quantum algorithm‐approximated time schemes, where the ON durations of each element are optimized to get the optimal radiation characteristics. The beamformer simultaneously aimed to cancel out or suppress the sidelobes of the scanned radiation patterns. The proposed beamformer is designed for an eight‐element antenna array, and the incorporation of time‐modulation and its inherent harmonics helps in simultaneous beam scanning over a desired region. The scanned patterns with reduced sidelobes are further exploited for the strategic null placement by proposing the time‐modulated single‐point jammers. The strategic null placement is nothing but the creation of a zero‐signal space in the angular region so that the interfering signals can be efficiently blocked by focusing on the intended signal. The concept is further extended, and the eight‐element array beamformer is developed for sectoral jamming mitigation to show the efficiencies, effectiveness, and robustness of the proposed research. Multiple sectors in the angular region are aimed by exploiting the harmonic beams suppressed below a desired level. The sidelobe canceling properties of the beamformer also show decent performance by suppressing the sidelobes below 20 dB for all the cases. The radiation power efficiencies of the proposed electronically controlled beamformer are more than 80%. The proposed sidelobe canceling time‐modulated beamformer is also compared with other related research for a comprehensive comparison.