We propose simple designs of compact patch antennas with bandwidth enhancement. Firstly, an inverted “L” strip is loaded onto the corner of one radiating patch edge to create an additional resonant mode which can be combined with that one of the conventional patch to enhance the operating bandwidth. Secondly, the “L” strip is replaced by inverted “T” strip to improve further the bandwidth by creating two adjustable resonant modes. The two proposed patch antennas have the particularity of enhancing the bandwidth significantly without increasing their profile and their overall sizes. Two antenna prototypes are fabricated and tested. Measurements reveal that the patch antenna loaded with “L” strip has stable radiation characteristics with 5.2 times enhancement in the relative bandwidth compared with a conventional patch antenna. The antenna loaded with inverted “T” strip has wider bandwidth (6.25 times wider than the conventional patch) and covers the operating band 5.07–5.89 GHz (15%) with measured peak gain and peak efficiency of 6.25 dBi and 78%, respectively. The proposed antennas are easy to fabricate, have a low-profile, and exhibit good performances which make them good candidates to use in real wireless applications.

中文翻译：

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通过加载倒“L”和“T”条带来增强紧凑型贴片天线的带宽

我们提出了具有带宽增强的紧凑型贴片天线的简单设计。首先，将倒“L”形条加载到一个辐射贴片边缘的拐角处，以创建一种额外的谐振模式，该模式可以与传统贴片的一种组合以提高工作带宽。其次，将“L”条替换为倒“T”条，通过创建两个可调谐振模式进一步提高带宽。两种建议的贴片天线具有显着提高带宽而不增加其外形和整体尺寸的特殊性。制作并测试了两个天线原型。测量表明，加载“L”形条带的贴片天线具有稳定的辐射特性，相对带宽比传统贴片天线提高了5.2倍。装有倒“T”形带的天线具有更宽的带宽（比传统贴片宽 6.25 倍），覆盖工作频段 5.07-5.89 GHz (15%)，测得的峰值增益和峰值效率分别为 6.25 dBi 和 78%。所提出的天线易于制造，具有低剖面，并表现出良好的性能，使其成为在实际无线应用中使用的良好候选者。