Compact MIMO antenna with metamaterial-based s-line decoupling stub for high isolation and multiband applications

This article presents a compact dual-band MIMO antenna integrated with an S-Line Decoupling Stub inspired by metamaterial principles, designed for wireless applications in the Sub-6 GHz and Ku/K-band ranges. The antenna operates at 3.5 GHz and 17 GHz, covering bandwidths of 3.43–3.69 GHz and 15.6–20 GHz, respectively. The novelty of this work lies in employing a single compact stub to suppress mutual coupling and enhance isolation without requiring periodic or multilayered structures. The antenna occupies a footprint of 20 × 13 × 1.6 mm 3 , making it suitable for integration into compact wireless platforms. Both simulated and measured results confirm excellent isolation (S 21 < –20 dB), low ECC (< 0.02), peak gain of 3.554dBi and stable radiation patterns. These attributes demonstrate the antenna’s potential for integration into 5G sub-6 GHz devices, K and Ku-band wireless systems, where compactness, multiband operation, and high isolation are critical.