A Metamaterial-Inspired Broadband Two-Element MIMO Antenna with Self-Isolation for 5G New Radios N77, N78, and N79

This work showcases a novel metamaterial-inspired broadband antenna system designed for 5G New Radio (NR) base station applications in bands N77, N78, and N79. The antenna features a three-layer structure with FR-4 dielectric substrates and copper conductors, achieving enhanced bandwidth and improved performance characteristics. Utilizing a slitted square patch loaded with a periodic 2D array of metamaterial elements, the antenna ensures excellent voltage standing wave ratio (VSWR) and reflection coefficient, with a bandwidth of 41.5% (3.19–4.86 GHz) and impedance matching (|S11| < −10 dB) across the targeted frequency bands. The antenna demonstrates resonant frequencies at 3.38, 3.88, 4.06, 4.58, and 4.72 GHz, with corresponding VSWR values ranging from 1.16 to 1.44. Simulated gain varies from −0.42 to 8.25 dBi, with radiation efficiency between 34.3% to 75.2% and total efficiency from 31.76% to 74.84%. Measurement results validate the simulated performance, confirming the antenna's suitability for 5G NR base station deployments. Additionally, a two-element Multiple Input Multiple Output (MIMO) configuration demonstrates high self-isolation (>16.94 dB), diversity gain (9.985–10 dB), and low channel capacity loss, ensuring robust performance in real-world scenarios. The antenna's wideband operation, excellent radiation characteristics, and high isolation make it a promising candidate for addressing the challenges of next-generation wireless communication systems.