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In this communication, a planar dual port multiple input multiple output antenna of size 1.2λ0 × 0.6λ0 × 0.008λ0 with LHCP/RHCP features is reported for the fifth-generation new radio n77/n78 sub-6 GHz wireless applications band. The single unit of the proposed design consists of a modified L-shape rectangular radiator with Z-shape slot loaded DGS. The defected ground structure is optimized through machine learning algorithms to achieve the maximum ARBW (output) by Right Shifting (RS) and left shifting (LS) the DGS and obtaining input features. The performance metric for ANN with ADAM optimizer was found to be optimal with MSE and R2 of 0.99 and 0.82, respectively. ANNs can leverage gradient information to guide the optimization process. This enables faster convergence towards optimal solutions compared to popular GAs and PSO, which are often gradient-free optimization methods. The MIMO configuration is achieved by creating a mirror image of the single unit about the x-axis. The salient features of the proposed design are (a) Impedance bandwidth (IBW) of 3.0–4.2 GHz covering the n77/n78 band, (b) 3-dB axial ratio bandwidth (ARBW) of the 2.6–3.9 GHz (c) Port-1 is generating RHCP while Port-2 is generating LHCP, results in polarization diversity. Different diversity performance parameters (ECC < 0.005, DG ~ 9.99 dB, and MEG < 3 dB) are in the optimum range confirming the proposed configuration as a suitable design for a MIMO radiator. [ABSTRACT FROM AUTHOR]

This work proposes a novel dielectric resonator antenna design for 5G-based IoT applications that operates in the sub-6 GHz frequency range. The DR antenna is built on a 1.6-mm-thick FR-4 substrate with dimensions of 30*50 mm2. The proposed dielectric resonator antenna is made of alumina and is excited using a microstrip feedline of 50 Ω. Because of the hybrid arrangement of cylindrical and rectangular dielectric resonator elements on the FR4 substrate, this proposed structure has improved the radiation mechanism. The antenna design process begins with creating the antenna in the Ansys HFSS EM simulator, which is then optimized using machine learning based on the antenna geometry's target factors. A data set of 2625 sample data values is generated in HFSS and fed to various machine learning algorithms for further optimization based on data trends. Post-optimization, the antenna design is fabricated and tested. The proposed antenna offers a wide bandwidth of 1.1 GHz between 3.5 and 4.6 GHz and resonates at 3.9 GHz making it suitable for 5G sub-6 GHz IoT applications. [ABSTRACT FROM AUTHOR]

Summary: A novel multiple‐input multiple‐output double asymmetrical cylindrical dielectric resonator antenna (MIMO‐DCDRA) with modified stub line feed is discussed and proposed in this work. Two unequal CDRA are placed diagonally to each other and are electromagnetically coupled with feeding arrangement via two asymmetrical circular apertures. By performing the optimization of the dimensional parameters, a significant impedance bandwidth of 70.84% ranging from 2.87 to 5.76 GHz and axial ratio bandwidth (ARBW) of 34.89% is obtained. Antenna gain is about 5.0 dBi within the operating frequency. The proposed MIMO‐DCDRA exhibits a low mutual coupling of (|S21| & |S12| < −20 dB) with the incorporation of a neutralization line. There are various diversity parameters that are also discussed in terms of mutual coupling, envelop correlation coefficient (ECC < 0.002), diversity gain (DG > 9.995), and channel capacity loss (CCL < 0.3 bits/s/Hz) over the entire impedance bandwidth. [ABSTRACT FROM AUTHOR]