Design of metamaterial-inspired multiport diamond-shaped MIMO antenna with dual interlocked rings for 5G NR n258 band applications

Abstract The proposed work demonstrates the design, simulation, analysis and validation of a low-profile, miniaturized four-element Multi–Input–Multi–Output MIMO antenna system optimized for 5G NR FR2 n258 band (24.25–27.5 GHz) Communication applications. The designed quad-element MIMO antenna structure comprises dual interlocked rings diamond-shaped radiator etched on a low-loss Rogers 5880 substrate having a thickness of 0.254 mm with a compact size of 12 × 24 mm 2 . Further, the gain and isolation of the proposed antenna is enhanced by incorporating an optimized metamaterial-based rectangular Split Ring Resonator (SRR) array structure between the adjacent element region. The proposed SRR unit cell structure is first optimized using unit-cell boundary conditions to exhibit high reflection and low transmission to reduce intercoupling between elements. Further, the S-Parameters, permittivity, permeability, and refractive index plots are analyzed to validate the behavior of SRR at the resonant frequency. Further, the radiation performance of MIMO antenna exhibiting peak realized gain (5.79 dB), radiation efficiency > 80%, with better isolation > 35 dB is demonstrated. Also, the diversity performance is validated achieving low Envelope Correlation Coefficients (ECC) < 0.001, Channel Capacity Loss (CCL) < 0.0025, Diversity Gain (DG) > 9.995 and Total Active Reflection Coefficient (TARC) < − 10 dB in the desired resonating band. Thus, the proposed quad-element MIMO antenna system simultaneously achieves low profile planar geometry, high isolation, robust radiation with better diversity performance as desired for next-generation mmWave communication applications.