A compact three‐antenna MIMO system based on a triangular half‐mode SIW cavity is proposed. Two isosceles‐right cavity edges are shorted by metallic vias while a hypotenuse is opened to radiate cavity energy into the air. By etching two T‐shaped slots and adopting coaxial feedings, three antennas are formed. The same operating frequencies are achieved by adjusting the position of these slots and high isolation is obtained by optimizing their length. The proposed design has attractive features of simple configuration and compact size, which is completely printed on a single‐layered substrate without external circuitries. A prototype with the overall size of 0.53λ₀ × 0.53λ₀ has been fabricated. Measured results exhibit the operating frequencies of about 3.51 GHz, high isolation of 16.0 dB, moderate gain of around 4.12 dBi, good radiation efficiency of 81.22%, and low envelope correlation coefficient of 0.16.

中文翻译：

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基于三角形半模基片集成波导腔的紧凑型三天线MIMO系统

提出了一种基于三角形半模SIW腔的紧凑型三天线MIMO系统。两个等腰右腔边缘通过金属通孔短路，同时打开斜边以将腔能量辐射到空气中。通过蚀刻两个T形槽并采用同轴馈电，形成了三个天线。通过调整这些插槽的位置可以获得相同的工作频率，并通过优化它们的长度来获得高隔离度。拟议的设计具有引人注目的特点，即配置简单，尺寸紧凑，可以完全印刷在单层基材上，而无需外部电路。原型具有0.53的整体尺寸λ ₀  ×0.53 λ ₀已经被捏造了。测量结果显示工作频率约为3.51 GHz，高隔离度为16.0 dB，中等增益为约4.12 dBi，良好的辐射效率为81.22％，低包络相关系数为0.16。