A miniaturized, loop resonators (LRs)‐loaded, circularly polarized (CP) multi‐dipole antenna with wide axial‐ratio (AR) beamwidth is proposed and demonstrated in this article. The radiator of this CP antenna consists of two pairs of parallel dipoles loaded with four LRs at their corners. By increasing the length of the LR, or decreasing the coupling space between the dipole and the LR, the effective length of the dipole can be lengthened significantly and thus the working frequency can be reduced without increasing the whole aperture size. As a result, a miniaturized radiator structure is completed. A feeding network consisting of a T‐shaped coupling feeding structure and four coplanar striplines having different lengths are specially designed to feed these dipoles with approximately the same magnitude and 90° phase quadrature. What is more, a cavity reflector is employed to achieve a unidirectional radiation with wide axial‐ratio beamwidth. The radiator of the proposed CP antenna has a small aperture size of only 0.34λ₀ × 0.34λ₀, where λ₀ is the free space wavelength at the working frequency. Measured results are in a good agreement with the corresponding simulated counterparts. Especially, the experimental results show that the antenna has achieved a wide AR beamwidth of 182° and 174° at the center frequency in the xoz and yoz planes, respectively.

中文翻译：

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通过加载回路谐振器具有宽轴向比波束宽度的小型化圆极化多偶极天线

本文提出并演示了一种小型，环形谐振器（LRs）加载，宽极化比（AR）束宽的圆极化（CP）多偶极天线。此CP天线的辐射器由两对平行偶极子组成，两对平行偶极子在其角上装有四个LR。通过增加LR的长度，或减小偶极子与LR之间的耦合空间，可以显着延长偶极子的有效长度，从而可以在不增加整个孔径的情况下降低工作频率。结果，完成了小型化的散热器结构。由T形耦合馈电结构和四个长度不同的共面带状线组成的馈电网络经过特殊设计，可以为这些偶极子提供大致相同的幅值和90°正交相位。更，腔反射器用于实现具有较宽轴向比光束宽度的单向辐射。建议的CP天线的辐射器的孔径只有0.34λ ₀  ×0.34 λ ₀，其中λ ₀是在工作频率的自由空间波长。测量结果与相应的模拟对应物吻合良好。尤其是，实验结果表明，该天线在xoz和yoz平面的中心频率处分别实现了182°和174°的宽AR波束宽度。