A 1 bit single-polarization broadband space-time-coding digital metasurface element with a zero cross polarization is proposed. This element consists of a modified patch, an electronic switch, a dc-bias network, a ground plane, and two-layer dielectrics. The upper patch with edge loading and centered square hole is fully optimized to achieve broadband and stable phase difference between two states. By electronically controlling the diode, the element achieves a 1 bit phase shift with a relative bandwidth of 20% within 180° ± 30° from 7.71 to 9.43 GHz. Moreover, a negligible cross polarization is obtained due to the uniaxial symmetry of the structure, and the amplitude loss is less than 0.8 dB for two states. The experimental results measured in a rectangular waveguide are well matched with the simulations, further demonstrating validity of the proposed element.

中文翻译：

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1位宽带空时编码数字超表面元件的设计


提出了一种零交叉偏振的1比特单偏振宽带空时编码数字超表面元件。该元件由修改后的贴片、电子开关、直流偏置网络、接地层和两层电介质组成。带有边缘加载和居中方孔的上部贴片经过全面优化，可实现两种状态之间的宽带且稳定的相位差。通过电子控制二极管，该元件在 7.71 至 9.43 GHz 的 180° ± 30° 范围内实现 1 位相移，相对带宽为 20%。此外，由于结构的单轴对称性，获得了可以忽略不计的交叉极化，并且两种状态的幅度损失均小于0.8 dB。在矩形波导中测量的实验结果与仿真非常吻合，进一步证明了所提出元件的有效性。