A new approach to controlling cross-polarization (XP), for either suppressing XP or exciting circular polarization (CP), in single-fed microstrip antennas using novel grid defected ground structures (GDGSs) is proposed. The key idea of GDGS is to construct defected ground structures (DGSs) from a grid of etched slots on a ground plane. The properties of each slot can be directly set by using either an open or short with fixed hardwires. The overall fixed hardwire configuration of the GDGS can be found straightforwardly by optimization of the XP or CP characteristics of the microstrip antenna. The importance of the approach is demonstrated by the results achieved. Results from two experimental prototypes are provided that demonstrate XP can be suppressed by 15 dB and CP can be excited with 78 MHz (2.2%) 3-dB axial ratio (AR) bandwidth and 6.6 dBic gain respectively on single-fed microstrip patch antennas.

中文翻译：

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非对称对称网格偏转地面结构增强微带天线的极化

提出了一种控制交叉极化（XP）的新方法，用于抑制XP或激发圆极化（CP），该方法使用新颖的网格缺陷接地结构（GDGS）在单馈微带天线中进行。GDGS的关键思想是从接地平面上的蚀刻槽网格构造缺陷接地结构（DGS）。可以通过使用固定硬线的开路或短路来直接设置每个插槽的属性。通过优化微带天线的XP或CP特性，可以直接找到GDGS的整体固定硬线配置。所获得的结果证明了该方法的重要性。提供了两个实验原型的结果，这些结果表明XP可以被抑制15 dB，CP可以在78 MHz（2.2％）3-dB轴向比率（AR）带宽和6的条件下被激励。