A dual operating (27/38 GHz) high performance 2 x 4 MIMO antenna array for 5G new radio applications

This article presents an unique configuration of Multiple-Input Multiple-Output (MIMO) antenna array for functioning at 27/38 GHz millimeter-wave 5G new radio (NR) frequency bands applications. The suggested antenna is constructed with four MIMO elements, containing total of eight identical patches arranged in a 2 x 4 array configuration. The array also includes a separate non-connected rectangular ground plane with an overall dimension of 32.4 x 32.8 x 0.8 mm(3). The single radiating patch elements are designed using spline resonator with H-shaped structures. The prototype model is realized using low cost FR-4 substrate and the obtained measurement results validate the analyzed simulated results. The suggested MIMO array antenna offers dual band operation with an impedance bandwidth of 8400 MHz covering 22 to 30.4 GHz and 8500 MHz ranging from 36.1 to 44.6 GHz. The proposed antenna achieves a peak gain of 8.75 dBi when operating at 27 GHz and 18.59 dBi at 38.1 GHz. Furthermore, it shows circular polarization characteristics by offering the axial ratio values significantly lower than 3 dB at 27 GHz and 38.1 GHz frequency bands. Additionally, the results indicate the favourable values of the diversity performance parameters with reference to Mean effective gain (MEG), Envelope correlation coefficient (ECC), Diversity gain (DG), Total active reflection coefficient (TARC), and Channel capacity loss (CCL). Moreover, it demonstrates high isolation (<-20 dB) within the desired bandwidth. These superior characteristics make it compatible for 5G NR frequency bands N257(26.5-29.5 GHz), N258 (24.5-27.5 GHz), N259 (39.5-43.5 GHz) and N260 (37-40 GHz), enabling its use in various countries including the China, European Union, Sweden, Korea, Japan, United States of America, Canada and Australia.