Compact Broadband Dual-Polarized Dielectric Resonator Antenna Array for 5G Low-Band Massive MIMO IoT and ISAC Applications

This article proposes a compact array based on a compact dielectric resonator antenna (DRA) element for massive multiple-input-multiple-output (MIMO) Internet of Things (IoT) and integrated sensing and communication (ISAC) applications at the low band. The DRA element is implemented with a small interelement distance in the vertical plane (0.3λ) to form three subarrays of 1 × 4 elements. With such a small distance, the coupling increases, and theoretically, the vertical half-power beamwidth cannot attain an average value of 33°. Therefore, to decrease the vertical half-power beamwidth (HPBW) and enhance the gain, three loaded conducting walls above the entire array, along with four vertical conducting side walls, are used. Moreover, the proposed array can steer the beam over a wide angle ranging from -40° to 40° with a gain variation of 2.4 dB. The measured results show a wideband (|S₁₁| ≤-10 dB) of almost 13% ranging from 720 to 820 MHz, port isolation in each subarray of more than 15 dB, isolation between subarrays of more than 17 dB, a gain of 9.5 dBi, an average vertical HPBW of 33°, and good radiation patterns. The diversity parameters, envelope correlation coefficient (ECC), and diversity gain (DG) are calculated and demonstrate good performance in the operating band. The proposed antenna array is well-suited for providing wide coverage and supporting a large number of IoT connections.