This letter presents a single-layer dual-circular-polarization reflectarray antenna with independent beam control for each polarization. First, a novel phasing approach, combining the variable-size approach and the element rotation approach together, is theoretically devised to achieve independent phase shifts for left hand circular polarized antenna (LHCP) and right hand circular polarized antenna (RHCP) waves. Then, a single-layer nested split-ring element has been designed as an example, and independent 360° phase shift for each circular polarization has been achieved. Finally, a Ka-band (20 GHz) reflectarray prototype with a circular aperture of 390 mm in diameter is designed, fabricated, and tested. Independent pencil beams radiating to the predesigned directions for each polarization were achieved. The measured gain is 35.5 dBi at –30° with the aperture efficiency of 52.7% for the LHCP excitation, and the measured gain is 35.4 dBi at 30° with the aperture efficiency of 51.6% for the RHCP excitation. The measured 1 dB gain bandwidths are 10.5% (19.4–21.5 GHz) and 10.0% (19.5–21.5 GHz) for the LHCP and RHCP excitations, respectively.

中文翻译：

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具有独立双 CP 波束控制的单层反射阵列天线

这封信介绍了一种单层双圆极化反射阵列天线，每个极化具有独立的波束控制。首先，从理论上设计了一种新的相位方法，将可变尺寸方法和元件旋转方法结合在一起，以实现左手圆极化天线 (LHCP) 和右手圆极化天线 (RHCP) 波的独立相移。然后，以单层嵌套裂环元件为例，实现了每个圆极化的独立360°相移。最后，设计、制造和测试了一个直径为 390 mm 的圆形孔径的 Ka 波段 (20 GHz) 反射阵列原型。实现了向每个偏振预先设计的方向辐射的独立笔形光束。测得的增益为 35。在–30° 时为 5 dBi，LHCP 激励的孔径效率为 52.7%，测得的增益为 30° 时为 35.4 dBi，RHCP 激励的孔径效率为 51.6%。对于 LHCP 和 RHCP 激励，测得的 1 dB 增益带宽分别为 10.5% (19.4–21.5 GHz) 和 10.0% (19.5–21.5 GHz)。