Broadband orbital-angular-momentum (OAM) multiplexing is of great interest due to its ability to increase channel capacity in wireless communications. However, broadband OAM-mode-reconfigurable transmitarrays have yet to be developed. Here, a broadband 1-bit electronically reconfigurable transmitarray for OAM-mode-reconfigurable beam generation is proposed, fabricated, and tested. The OAM transmitarray includes $20\times 20$ elements with a 1-bit phase resolution, each element is controlled by two $p$-$i$-$n$ diodes with a minimum insertion loss of 0.9 dB and a 3-dB transmission bandwidth of 17.1%. A nearly perfect 1-bit phase resolution is obtained by reversing the current. The OAM mode can be switched between $l=+1$ and $l=+2$ based on a steering-logic board. Both simulation and experiment results show the transmitarray can generate a broadband OAM-mode-reconfigurable beam from 9.5 to 10.5 GHz. The proposed transmitarray may have potential applications in broadband OAM-multiplexing communications.

中文翻译：

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宽带1位电子可重构发射阵列产生的轨道角动量模可重构光束

宽带轨道角动量（OAM）复用由于其能够增加无线通信中的信道容量而备受关注。但是，尚未开发宽带OAM模式可重配置的发射阵列。在这里，提出了一种用于OAM模式可重构波束生成的宽带1位电子可重构发射阵列，并进行了测试。OAM发送阵列包括$20\times 20$ 具有1位相位分辨率的元件，每个元件由两个控制 $p$--$\mathrm{一世}$--$ñ$二极管的最小插入损耗为0.9 dB，3 dB的传输带宽为17.1％。通过反转电流可获得接近完美的1位相位分辨率。OAM模式可以在以下两种模式之间切换$升=+\mathrm{1个}$ 和 $升=+\mathrm{2个}$基于转向逻辑板。仿真和实验结果均表明，发射阵列可以产生9.5至10.5 GHz的宽带OAM模式可重配置波束。提出的发射阵列在宽带OAM多路复用通信中可能具有潜在的应用。