In this letter, a miniaturized triband printed monopole antenna with circular polarization (CP) characteristic has been designed and demonstrated. The proposed geometry is comprised of two orthogonal stubs and one meander pattern on the top layer and a defected ground plane. By carefully designing the top and bottom layer topologies, the antenna is made significantly compact having an overall size of 0.26λ × 0.28λ × 0.017λ, where λ denotes the free space wavelength at the lowest CP frequency. The geometry exhibits a wide 10-dB impedance bandwidth of 53.63% (3.22–5.58 GHz) covering three distinct CP resonances appearing at 3.30, 4.50, and 5.40 GHz. The structure has been fabricated and the measured responses show a reasonable agreement with the simulated results. The proposed antenna has a simple topology, broadside radiation, moderate gain, and an improved miniaturization performance as compared to the earlier reported multi-band CP antennas.

中文翻译：

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紧凑型三频圆极化曲流加载单极天线

在这封信中，设计并演示了具有圆极化 (CP) 特性的小型化三频印刷单极天线。建议的几何结构由两个正交短截线和顶层上的一个曲折图案和有缺陷的接地平面组成。通过精心设计顶层和底层拓扑，天线变得非常紧凑，整体尺寸为 0.26λ × 0.28λ × 0.017λ，其中 λ 表示最低 CP 频率下的自由空间波长。该几何结构表现出 53.63% (3.22–5.58 GHz) 的 10-dB 阻抗带宽，涵盖了出现在 3.30、4.50 和 5.40 GHz 的三个不同的 CP 共振。结构已经制作完成，测量的响应与模拟结果显示出合理的一致性。建议的天线具有简单的拓扑结构、宽边辐射、中等增益、