Using the method of moments, we investigate two types of circularly polarized loop array antennas with and without a coplanar feedline (CF). The loops and the CF are located above a ground plane at a height of a quarter-wavelength. First, we analyze decoupling two-element array antennas. It is found that the antennas with and without the CF show reduced cross-polarization levels of -15 and -16 dB, respectively, when compared with that (-8 dB) of a conventional two-element array antenna without a CF. Next, we analyze sequential two-element array antennas. It is revealed that the antennas with and without a CF have bandwidths of 23% fora 3dB axial-ratio criterion and 49% for a 3dB gain-drop criterion, respectively. The analysis results are validated by an experimental work.

中文翻译：

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解耦和序列阵列天线共面馈线对辐射特性的影响


使用矩量法，我们研究了两种类型的带和不带共面馈线 (CF) 的圆极化环形阵列天线。环路和 CF 位于接地平面上方四分之一波长的高度。首先，我们分析去耦二元阵列天线。结果发现，与不带 CF 的传统两元件阵列天线 (-8 dB) 相比，带和不带 CF 的天线的交叉极化水平分别降低了 -15 和 -16 dB。接下来，我们分析顺序二元阵列天线。结果表明，带和不带 CF 的天线在 3dB 轴比标准下的带宽分别为 23%，在 3dB 增益下降标准下的带宽分别为 49%。分析结果通过实验工作得到验证。