A Multi-beam Reflectarray Antenna with the Genetic Algorithm Optimizing Beams

In this paper, a multi-beam reflectarray antenna with three beams is proposed. The reflectarray is composed of 25×25 units, and each unit can provide a 0 to 370° phase-shift range by changing the size of the patches. The distribution of the phase on the reflectarray is obtained with the genetic algorithm (GA) which is applied to generate the desired beams. To verify the design, a reflectarray with three fixed feeds is simulated in High Frequency Structure Simulator (HFSS). The simulated results agree well with the calculated results. The simulated first sidelobe level (SLL) of each beam is less than -13 dB, and the simulated beam directions are -7°, 0°, and 7°, respectively.