Multi-Beam Radiation in Time-modulated SIW-DRA linear array

This paper introduces time-modulated linear array for beam-switching and multi-beam synthesis using particle swarm optimization (PSO). The array consists of 16 elements spaced by 0.45λ. Each element is a compact planar DRA based on substrate integrated waveguide technology (SIW). The SIW-DRA single element operates at 10 GHz with peak gain of 5.8 dBi and broadside wide beam. The time-modulation of the array sequence is used to switch the beam of the 1st-harmonic frequency at different directions. Analytical solutions of periodic switching sequences for different patterns are developed. The PSO is used to estimate the on-time sequence of the array to radiate multi-beams at the 1st-harmonics and a single beam at the fundamental frequencies. Single, dual, triple and quad-beams are designed. An isotropic array is designed to compare their results with the SIW-DRA array.