ABSTRACT In this paper, a novel single-layer reflectarray antenna that converts linear polarization to circular polarization is presented. The reflectarray unit-cell consists of a microstrip circular patch inside a ring. Two curved and stub lines are attached to the patch. The element converts the linearly polarized incident wave to two orthogonal linearly polarized reflected waves. The length of the phase-delay lines control the phase shift of each component. Circular polarization is obtained by introducing a 90° phase difference between the two orthogonal components of the reflected wave. The proposed element provides a linear phase response in the range of 11–13.4 GHz. Measurement results of the fabricated reflectarray antenna show a maximum circular polarization gain of 27 dBi at 12.4 GHz. The gain at the center frequency (12.2 GHz) is 26.1 dBi with 11% 1-dB bandwidth. The measured axial ratio is less than 3 dB in the band 11.6–12.9 GHz. The sidelobe level (SLL) is lower than −19 dB and the polarization isolation is better than 17 dB over 11.6–12.8 GHz.

中文翻译：

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线性到圆偏振转换器单层反射阵列天线

摘要 在本文中，提出了一种新型单层反射阵列天线，可将线极化转换为圆极化。反射阵列单元由环内的微带圆形贴片组成。贴片上附有两条弯曲的短线。该元件将线偏振入射波转换为两个正交的线偏振反射波。相位延迟线的长度控制每个组件的相移。通过在反射波的两个正交分量之间引入 90° 相位差来获得圆偏振。提议的元件在 11-13.4 GHz 范围内提供线性相位响应。制造的反射阵列天线的测量结果显示，在 12.4 GHz 时的最大圆极化增益为 27 dBi。中心频率 (12.2 GHz) 处的增益为 26。1 dBi 和 11% 1-dB 带宽。在 11.6–12.9 GHz 频段内测得的轴比小于 3 dB。在 11.6–12.8 GHz 范围内，旁瓣电平 (SLL) 低于 -19 dB，极化隔离优于 17 dB。