一种基于AFSS的可重构天线设计

针对5G智能天线双频工作，提出一种基于有源频率选择表面（active frequency selective surface, AFSS）的可重构天线，该天线由蝶形频率可重构馈源和八棱柱形AFSS构成，馈源采用的是共面波导方式馈电的蝶形单极子. AFSS由对称弯钩状缝隙的周期结构构成，通过PIN二极管进行加载，使得AFSS能够在3.4～3.6 GHz和4.8～5.0 GHz两个5G频段互为反射模式和透射模式. 利用AFSS对馈源天线激励的电磁波进行空间调控，可实现两个频段的全向和定向波束的切换，也可实现水平面波束扫描. 根据仿真设计的天线模型进行设计加工和实际测试，结果表明:该天线的工作频段可以覆盖以上两个频段，低频定向波束增益为7.6 dBi，高频定向波束增益为8.6 dBi；并且能实现高/低频双波段切换、全向/定向波束切换和水平面内360°波束扫描功能. 该天线具有波束切换灵活、功耗低、造价低等特点，在新一代无线通信系统中具有一定的应用价值.

A reconfigurable antenna design based on AFSS

Aiming at the dual-frequency operation of 5G smart antennas, a reconfigurable antenna based on active frequency selective surface is proposed. The antenna consists of a frequency reconfigurable feed antenna in the shape of a bow-tie and a cylindrical active frequency selective surface (AFSS). The feed antenna adopts a coplanar waveguide feed of bow-tie shaped monopole. The active frequency selection surface consists of a periodic structure with a symmetrical hook-shaped slot, which is loaded by a PIN diode, enabling AFSS to be in reflection mode and transmission mode in the two 5G frequency bands 3.4?3.6 GHz and 4.8?5.0 GHz. By using this AFSS, the electromagnetic waves excited by the feed antenna can be spatially controlled, and the omnidirectional and directional beam switching of the two frequency bands can be realized, and the horizontal plane beam scanning can also be realized. Processed and tested according to the simulated antenna model, the test results show that the working frequency band of the antenna covers the above two frequency bands, a low-frequency directional beam gain of 7.6 dBi, and a high-frequency directional beam gain of 8.6 dBi; and can achieve high/low frequency dual-band switching, omnidirectional/directional beam switching and beam scanning within 360° in the horizontal plane. This antenna has the characteristics of flexible beam switching, simple structure, easy processing, low power consumption, low cost, and it has certain application value in 5G new generation wireless communication system.