Compact and directional dual band antenna with low mutual coupling MIMO configuration for mm-wave communication

• Compact dual-band antenna covers 28 GHz and 38 GHz mm-wave 5G spectrums. • Wideband performance achieved with modified T-shaped radiator and stubs. • MIMO configuration offers low mutual coupling (< −20 dB) without decoupling structures. • High gain (6.2–8.9 dBi) and stable directional radiation in both bands. • Simplified structure ensures easy fabrication and strong MIMO performance metrics.. A compact dual band antenna and its multiple input multiple output (MIMO) configuration is presented in this article to meet the requirements of devices operating in mm-wave band spectrum of 28 GHz and 38 GHz. Wideband behavior is achieved using a modified T-shaped radiator loaded with stubs while the compactness in structure is achieved by deploying various stubs. The antenna comprises of 15 × 15 mm 2 which corresponds to 1.4λ 0 × 1.4λ 0 , where λ 0 represents the lower resonating frequency of 28 GHz. Broadband behavior is observed at both targeting frequencies of 28 GHz and 38 GHz with respective measured bandwidth of 22.5–29.7 GHz (25.7 %) and 34.8–44.8 GHz (20.4 %) and peak gain of 8.9 dBi and 8.7 dBi. The proposed work offers directional and stable radiation patterns at both pass band regions. Moreover, to fulfill the need of MIMO system, the antenna design is further extended to its 2 × 2 MIMO configuration by placing the antennas orthogonal to each other. This configuration results in low mutual coupling of < -20 dB, without utilizing any decoupling structure, resulting in simple structured antenna which reduces the fabrication errors for mass production. Along with that the proposed MIMO antenna offers strong performance parameters having measured envelope correlation coefficient (ECC) <0.2, measured diversity gain (DG) of > 9.75. Furthermore, the comparison with literary works highlights the novelty of the presented work by offering dual-band coverage globally for 5G applications having compact size, high gain and stable radiation patterns.