Dual-Band Quad-Element mmWave MIMO Antenna with Parallel-Aligned Slots for 5G Applications

This study presents the design of a dual-band MIMO antenna for 5G mm-Wave communication, operating at 28 GHz and 32 GHz. The proposed antenna, measuring 20×20×0.8 mm³ and using a Rogers RT Duroid 5880 substrate, whose permittivity is 2.2, is incorporated rectangular slots to achieve dual resonance at 27.98 GHz and 32.02 GHz with return losses of -36.2 dB and -38 dB, respectively. The dual-band operation is achieved through an optimized microstrip patch design that incorporates two slots into the patch structure. The inset feed configuration is further enhanced the antenna’s performance by providing better impedance matching and improved bandwidth characteristics. It is achieved peak gains of 7.84 dBi and 4.25 dBi at 27.98 GHz and 32.02 GHz. Additionally, the proposed dual-band MIMO antenna is demonstrated superior performance with an envelope correlation coefficient (ECC) of less than 0.000036, indicating minimal mutual interference between antenna elements. Total active reflection coefficient (TARC) is below -20 dB. The channel capacity loss (CCL) is maintained under 0.06 bits/sec/Hz, and the mean effective gain (MEG) is approximately -3.03 dB and -3.06 at respected resonant frequency. It achieves a diversity gain (DG) of approximately 9.99 dB and exhibited isolation between elements exceeding -22.5 dB.