Abstract This paper presents a compact, reconfigurable sub-6 GHz MIMO antenna array integrated with a solar panel, targeting energy-efficient and sustainable 5G communication networks. The proposed design addresses the critical challenges of antenna performance degradation and mutual coupling that typically arise when antennas are integrated with photovoltaic structures. To overcome these limitations, the antenna employs a metamaterial (MTM) radiating patch composed of a 5 × 3 Hilbert-curve split-ring resonator (SRR) array, which enhances impedance bandwidth and gain through plasmonic resonance behavior. Additionally, a defected electromagnetic band-gap (EMBG) ground plane is introduced to suppress surface waves and back radiation, thereby improving radiation efficiency and isolation. A novel composite right/left-handed (CRLH) isolation wall is incorporated between antenna elements to achieve strong mutual coupling reduction within an ultra-compact footprint. Frequency reconfigurability is realized using PIN diodes, enabling dynamic control of the operating bands and radiation characteristics. The proposed two-element MIMO configuration is mounted beneath a solar panel, demonstrating negligible impact on photovoltaic I–V characteristics, while simultaneously providing a gain enhancement due to constructive electromagnetic interaction. The antenna operates over a wide frequency range between 2.7 and 6.0 GHz and beyond, with resonances around 3 and 5 GHz, achieving a maximum gain of approximately 7.3 dBi.
Al-Attar et al. (2026) studied this question.