High-gain bidirectional radiative circularly polarized antenna based on focusing metasurface

Abstract

A high-gain bidirectional radiative circular polarization (CP) antenna loaded with a dual-mode focusing metasurface (MS) is proposed. The original microstrip patch antenna consists of two coaxially fed tangential patches with different sizes, enabling CP radiation at 8.15 GHz and 14.8 GHz with the gain of 5.4 dBic and 6.2 dBic, respectively. The unit-cell of the focusing MS is composed of two metallic layers separated by a dielectric substrate based on geometric phase principle, which can independently tailor the focusing effect of transmitted and reflected CP waves at 8.15 GHz and 14.8 GHz, respectively. Then, the high-gain bidirectional radiation antenna can be formed by combining the original CP microstrip antenna and focusing MS. The final designed antenna can achieve a CP radiation converge characteristic in transmission at 8.15 GHz with a peak gain of 15.9dBic, and at 14.8 GHz with a peak gain of 19.4dBic in refection, respectively. In order to verify the feasibility of the proposed design, the bidirectional radiative CP antenna with/without focusing MS were fabricated and measured, and the results are consistent basically with the simulated ones. The proposed bidirectional focusing MS antenna could provide an effective solution for dual-mode radiation and high-rate information transmission of the communication system.