A miniaturized tri‐polarized MIMO slot antenna loaded with slit‐postwall‐slot step impedance resonator (SIR) is proposed. The SIR, which shortens the length of radiation slot for the miniature purpose, consist of two slit‐slot lines with high impedance and a slit‐postwall‐slot line with low impedance, because the postwall can decrease the characteristic impedance of slit‐slot line. Meanwhile, the slits can improve the polarization purity and isolation of the antenna array effectively. Compared with the conventional slot antenna array, the measured results of proposed antenna array shows that the cross‐polarization ratio has improved 2 dB on H plane and 3 dB on E plane at 2.45 GHz, while the lengths of ground plane and slot are shortened 77.8% and 77%, respectively. Furthermore, the proposed antenna array operates at dual band and the isolation are −22 dB at 2.45 GHz and ‐27 dB at 4 GHz. The performance and structure of the proposed antenna array can be applied for the condition of high polarization purity and demanding volume.

中文翻译：

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微型三极化MIMO缝后壁步进阻抗谐振器缝隙天线阵列

提出了一种带有狭缝-后壁-狭缝步进阻抗谐振器（SIR）的小型化三极化MIMO缝隙天线。SIR缩短了微型辐射槽的长度，它由两条高阻抗的缝隙线和一条低阻抗的缝隙-墙后-缝隙线组成，因为后壁会降低缝隙线的特征阻抗。同时，狭缝可以有效地提高极化纯度和天线阵列的隔离度。与传统的缝隙天线阵列相比，所提出的天线阵列的测量结果表明，在2.45 GHz时，交叉极化比在H平面上提高了2 dB，在E平面上提高了3 dB，而接地平面和缝隙的长度缩短了77.8。 ％和77％。此外，建议的天线阵列工作在双频段，并且在2.45 GHz时隔离度为−22 dB，在4 GHz时隔离度为‐27 dB。所提出的天线阵列的性能和结构可以用于高极化纯度和要求体积的条件。