Yu Jiayu, Zheng Qiurong, Tang Xueqin, He Jie, Liu Jie, Zhang Bin, Zou Kun
Information and Navigation College, Air Force Engineering University, Xi'an 710077, China.
Joint Logistics College, PLA National Defense University, Beijing 100117, China.
Micromachines (Basel). 2022 Jul 15;13(7):1117. doi: 10.3390/mi13071117.
Increasing information capacity is significant for high-speed communication systems in a congested radio frequency sequence. Vortex waves carrying mode orthogonal orbital angular momentum (OAM) have gained considerable attention in recent years, owing to their multiplexing quality. In this study, a broadband Pancharatnam-Berry (PB) metasurface element with a simple structure is proposed, which exhibits an efficient reflection of the co-polarized component and a full 2π phase variation in 10.5-21.5 GHz under circularly polarized wave incidence. By convolution and addition operations, the elaborate phase distribution is arranged and the corresponding metasurface-reflecting dual-mode asymmetric dual-OAM waves is constructed. Under continuous control of the working frequency, the OAM vortex beams with the topological charges 1 and -1 are steered to scan within the angle range of 11.9°-24.9° and 17.9°-39.1° at = 315° and 135° planes, respectively. The simulation and measurement results verified the feasibility of generating frequency-controlled asymmetric dual beams and the validity of dual-mode OAM characteristics, both in the near and far fields. This design approach has considerable potential in OAM wave multiplexing and wireless communication system transmission.
在拥挤的射频频段中，增加信息容量对高速通信系统至关重要。近年来，携带模式正交轨道角动量（OAM）的涡旋波因其复用特性而备受关注。在本研究中，提出了一种结构简单的宽带潘查拉特纳姆 - 贝里（PB）超表面元件，该元件在圆极化波入射下，对共极化分量表现出高效反射，并在10.5 - 21.5 GHz范围内呈现出完整的2π相位变化。通过卷积和加法运算，安排了精细的相位分布，并构建了相应的反射双模式非对称双OAM波的超表面。在工作频率的连续控制下，拓扑电荷为1和 -1的OAM涡旋光束分别在 = 315°和135°平面内，在11.9° - 24.9°和17.9° - 39.1°的角度范围内进行扫描。仿真和测量结果验证了在近场和远场中产生频率控制非对称双光束的可行性以及双模式OAM特性的有效性。这种设计方法在OAM波复用和无线通信系统传输方面具有相当大的潜力。
