Amplitude- and phase-tailorable metasurface for circularly polarized low side-lobe antenna design

Pancharatnam-Berry (PB) metasurfaces are capable of flexibly tailoring circularly polarized waves but still limited to the phase-only control. Here, we present a new strategy for realizing simultaneous amplitude and phase control of circularly polarized waves by combining propagation phase and the PB counterpart. As a proof of concept, a well-engineered spatial phase and amplitude distribution, which obeys the Tailor distribution, is employed to actualize a circularly polarized low side lobe antenna around 14 GHz. The finally assembled antenna well validates our strategy of simultaneous amplitude and phase control, achieving a directive beam of 20 dB with side lobe levels uniformly below -22.5 dB at 14 GHz. The proposed novel strategy for simultaneous amplitude and phase control of circularly polarized waves may pave the way for many fascinating meta-devices.