In this letter, a high-gain circularly polarized (CP) array antenna with low profile and low grating lobe property is proposed. The array is composed of high-gain and low sidelobe CP patch elements based on odd high-order modes. By adding perturbation structure, a pair of orthogonal modes (TM ₃₀ /TM ₀₃ ) of the patch with 90° phase difference is diagonally excited. Meanwhile, by introducing five circular slots on the patch, four sidelobes of the element radiation pattern in x o z plane and y o z plane are effectively reduced. Consequently, the large grating lobes of array antenna can be avoided. Then, a 2 × 2 array prototype is designed and fabricated for verification. The thickness of array is only 0.5 mm (0.027 λ ₀ ). The peak gain and aperture efficiency reach up to 17.5 dBic and 55.5%, respectively. When the element spacing is more than 1 λ ₀ , the measured maximum grating lobe level at 16.25 GHz is only −15 dB.

中文翻译：

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基于TM ₃₀ / TM ₀₃模式的低栅瓣特性高增益圆极化阵列天线

在这封信中，提出了一种具有低轮廓和低栅瓣特性的高增益圆极化（CP）阵列天线。该阵列由基于奇高阶模式的高增益和低旁瓣CP补丁元素组成。通过添加扰动结构， 具有90°相位差的贴片的一对正交模式（TM ₃₀ / TM ₀₃）被对角激发。同时，通过在贴片上引入五个圆形槽，可以将元素辐射图的四个旁瓣X Ø ž 飞机和 ÿ Ø ž飞机被有效减少。因此，可以避免阵列天线的大栅瓣。然后，设计并制造了一个2×2阵列原型以进行验证。阵列的厚度仅为0.5毫米（0.027 λ ₀ ）。峰值增益和孔径效率分别达到17.5 dBic和55.5％。当元素间距大于1时 λ _0时 ，在16.25 GHz处测得的最大光栅波瓣电平仅为-15 dB。