Enhanced isolation unique fractal diminutive MIMO antenna with identical elliptical notch and cross stub for wireless uses

This work discusses the concept, simulation, and experimental validation of a compact ultra-wideband (UWB) fractal-based multi-input multi-output (MIMO) antenna. MIMO antenna is fabricated on an FR-4 layer for current wireless connectivity uses. The proposed antenna is formed by four elliptical radiating elements, each incorporating an identical elliptical notch organized in a rotating orthogonal orientation. A U-slot with a cross-shaped modified ground structure is introduced to enhance isolation and impedance resembling. The fractal MIMO antenna occupies a tiny size of 0.5λ × 0.5λ × 0.016λ (at 3.1 GHz) and operates over an extensive spectrum that spans from 3 GHz to 24 GHz, which makes it appropriate for various wireless technologies. The measured and simulated findings show outstanding performance throughout the operational bandwidth, with a return loss at several resonance points < -10 dB, apart from the notch frequency. To ensure optimal MIMO functioning, the suggested configuration generates a diversity gain surpassing 9.98, a minimal envelope correlation coefficient (ECC < 0.004), and high isolation ( ≤ - 21 dB). The antenna's gain exceeding 2 dBi further validates its appropriateness for contemporary portable networks of communication, including satellite communications, radar, 5G, and the Internet of Things. The promising fractal MIMO antenna's ability to achieve small dimensions, broad performance, and better isolation is confirmed by the high agreement between modelling and experimental findings.