Dispersion-engineered compact metasurface antenna achieving wideband circular polarization

A compact wideband circularly polarized metasurface antenna based on dispersion-engineered unit cells and sequential rotation is presented. The design employs a compact 2 × 2 truncated metasurface element as the basic circularly polarized resonator. Dispersion analysis is used to clarify the unit-cell modal behavior and guide the compact element design. Four elements are sequentially rotated and excited by a compact one-port aperture-coupled feeding network to improve the axial-ratio bandwidth while maintaining a reduced aperture size. The fabricated prototype achieves a measured impedance bandwidth of approximately 40% at -10 dB and a measured axial-ratio bandwidth of 23.8%, covering 4.8-6.1 GHz. The measured peak gain is 9.16 dBic, with an overall antenna size of 1.12 λ0 × 1.12 λ0. These results demonstrate compact size, wideband impedance matching, and right-hand circular polarization, making the antenna suitable for wireless and satellite communication systems.