In this letter, a complementary split‐ring array (CSRA) for decoupling compact (edge‐to‐edge spacing of 0.078 λ₀) 2 × 2 circularly polarized (CP) microstrip antenna is proposed. The CSRA is the ground plane with the etched split‐ring array (SRA) which is composed of 12 split‐rings. Each element is surrounded by four etched split‐rings, and the two adjacent elements share the same etched split‐ring between them. The decoupling mechanism of the CSRA is to alter the amplitude and phase of the original coupling field and make the polarization of the adjusted coupling field mismatch with the receiving field. To verify the idea, the 2 × 2 CP antennas with and without CSRA are simulated and measured. The experimental results show that the maximum mutual coupling reduction is 29.6 dB for S₁₂, 23.6 dB for S₁₄, and 5.6 dB for S₁₃. Meanwhile, the impedance bandwidth and radiation characteristics remain almost unchanged. The measured results agree well with the simulated results, which showed new light on application of the proposed CSRA for multiple‐input‐multiple‐output systems.

中文翻译：

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互补的开口环阵列，用于紧凑的去耦2×2圆极化天线

在这种信，互补开口环阵列（CSRA）去耦紧凑（0.078边缘到边缘间距λ ₀）2×2圆偏振光（CP）微带天线算法。CSRA是带有蚀刻开口环阵列（SRA）的接地平面，该阵列由12个开口环组成。每个元素被四个蚀刻的开口环包围，并且两个相邻的元素在它们之间共享相同的蚀刻的开口环。CSRA的去耦机制是改变原始耦合场的幅度和相位，并使调整后的耦合场的极化与接收场不匹配。为了验证该想法，模拟并测量了带有和不带有CSRA的2×2 CP天线。实验结果表明，S ₁₂的最大互耦减小为29.6 dB，对于S ₁₄为23.6 dB，对于S ₁₃为5.6 dB 。同时，阻抗带宽和辐射特性几乎保持不变。实测结果与模拟结果吻合良好，这表明拟议中的CSRA在多输入多输出系统中的应用有了新的亮点。