A low-profile microstrip patch antenna with pattern diversity is proposed. In our design, even- and odd-order modes are employed to enhance the impedance bandwidth for the conical and broadside radiation beams, respectively. Initially, an array of concentric shorting pins is introduced to reallocate the resonant frequencies of TM ₀₁ , TM ₁₁ , and TM ₀₂ modes closely to each other. Then, a longitudinal slot and a novel metallic disk are utilized to reduce the frequency of its TM ₁₂ mode, while their influences on the antenna gain are extensively studied. Moreover, two original shorting pins are modified to further push up the resonant frequency of TM ₀₁ mode. Furthermore, in-phase and out-of-phase signals provided by the feeding scheme are introduced to excite even- and odd-order modes, respectively, thus guaranteeing the high isolation and realized gain. Finally, a prototype is fabricated and measured to verify the simulated results. Good agreements between the measured and simulated results are observed, indicating good performances with a wide overlapped impedance bandwidth of around 9% ranging from 2.38 to 2.60 GHz and a high gain of around 6.5 dBi for the conical beam and 8.8 dBi for the broadside beam. Most importantly, these attractive performances are obtained with a low profile of only 0.033 λ ₀ ( λ ₀ is the wavelength at 2.49 GHz).

中文翻译：

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使用偶数阶和奇数阶模式具有增强的带宽和模式分集的薄型微带贴片天线

提出了一种具有方向图分集的低剖面微带贴片天线。在我们的设计中，偶数阶和奇数阶模式分别用于增强锥形和宽边辐射束的阻抗带宽。最初，引入一组同心短路引脚以重新分配彼此接近的TM ₀₁ 、TM ₁₁ 和TM ₀₂模式的谐振频率 。然后，利用纵向缝隙和新型金属盘来降低其 TM ₁₂模式的频率 ，同时广泛研究了它们对天线增益的影响。此外，修改了两个原始短路引脚以进一步推高TM ₀₁的谐振频率 模式。此外，引入馈电方案提供的同相和异相信号分别激发偶数阶和奇数阶模式，从而保证高隔离度和实现的增益。最后，制造和测量原型以验证模拟结果。观察到测量和模拟结果之间的良好一致性，表明具有良好的性能，在 2.38 至 2.60 GHz 范围内具有约 9% 的宽重叠阻抗带宽，锥形波束的高增益约为 6.5 dBi，宽边波束的增益约为 8.8 dBi。最重要的是，这些吸引人的性能是通过仅 0.033 的低轮廓获得的λ ₀ ( λ ₀是 2.49 GHz 处的波长）。