Novel Phase Distributions for Large Beam- Scanning Reflectarrays
Abstract In this paper, the hybrid combination of genetic algorithm and particle swarm optimization (GAPSO) is used to optimize the phase distribution (PD) of beam-scanning reflectarray. The GAPSO takes advantage of both conventional algorithms and it could cover their weaknesses. Two novels PDs are proposed in this paper. Constant phase elements (CPEs) and ordinary elements (OEs) are two basic kinds of elements used in these two novel PDs. The phases of CPEs are fixed and it is not changed during beam scanning and only OEs’ phase could be adjusted to scan the main beam. GAPSO and two novels PDs are applied to array factor PD of a 30*30 reflectarray antenna to displace the main beam electronically in the vertical plane from-40⁰ to 40⁰. In these two novel PDs, 28.8% of total elements are selected as CPEs. In the first one with only CPEs, the phase of OEs (71.2% of total elements) could adjust, but in the second novel PD with CPEs and phase symmetry plane 35.5% of the total elements’ phase could be changed to scan the beam. Optimization results show that the novel PD and hybrid algorithm have appropriate performance in the electronically beam scanning of reflectarrays.