Multi-Harmonic Beam Steering of TMLAA Employing TLBO

Abstract

This paper aims to address the utilization of harmonic beams radiated from the Time-Modulated Linear Antenna Array (TMLAA) by focusing the beams in the Angle of Arrival (AoA) direction. The focusing of the first and second harmonic beams with adequate power is achieved by employing the optimized switching schemes. The switching sequence ON duration optimization is conducted by Teaching Learning Based Optimization (TLBO). The optimization is conducted for three cases, to steer the first positive harmonic beam to 30°, 45°, and 60°. The performance of the TLBO is compared with the evolutionary algorithms Differential Evolution (DE) and Particle Swarm Optimization (PSO). TLBO optimization results in sidelobe level (SLL) in fundamental and harmonic beams below −15 dB. The simulation results convey that the TLBO performs superior to DE and PSO in focusing the harmonic beams in the AoA direction with suppressed SLL and enhanced power.