Low-Sidelobe Dual-Beam Antenna Based on Metasurface With Independently Regulated Amplitude/Phase

A method to design low-sidelobe dual-beam antennas is proposed based on metasurface with independently regulated amplitude/phase. This method includes the following steps. First, a standard horn antenna is modeled and the amplitude and phase of the radiation field at the interface are obtained. Next, the phase compensation technology based on the actual radiation phase of the feed is employed to control directions of the main lobe. Finally, the reflection amplitude of metasurface is controlled by combining Schelkunoff polynomials and actual radiation amplitude of the feed. Specifically, by mapping the angles of the dual beams to the complex coordinate system, the sidelobe level of the dual-beam antenna is reduced. Meanwhile, a compensation factor is introduced to offset the gain loss caused by amplitude modulation.