Multi-Beam Radiation Intensity Control of a Reflectarray Antenna Using Unit Cell Arrangement

In this paper, multi-beam radiation intensity control of a reflectarray antenna by means of unit cell arrangement is proposed and investigated. A metasurface is designed to achieve reflection in a specific direction, and a circular ring structure with a ground plane is employed as the unit cell of the designed metasurface. To achieve multi-beam reflection, the designed unit cells are rearranged in either a linear alternating pattern or a checkerboard pattern. Furthermore, the radiation intensity of the reflected beams is controlled by adjusting the number of unit cells. The operation frequency is 8.2 GHz, and the reflectarray antenna is fed by a rectangular horn antenna with a gain of 9 dBi. To demonstrate the feasibility of the proposed structure, a dual-beam reflectarray antenna with beam-forming angles of −30° and 60° is designed, and reflectarray antennas featuring checkerboard and linear alternating configurations with a unit cell ratio of 1:2 are fabricated and measured. The measured and simulated results are found to be in good agreement, confirming that a higher unit cell ratio can achieve greater reflection gain, even at large beamforming angles.