Highly Compact Dual-Band Four-Port Integrated Lens MIMO Antenna for 5G New Radio IoT Devices

Abstract

This article introduces a highly compact, dual-wideband four-port MIMO antenna with an integrated 3D-printed dielectric lens, tailored for 5G millimeter-wave (mmWave) new radio (NR) IoT applications. The antenna's gain and port isolation are significantly enhanced by placing a hemispherical dielectric lens atop the MIMO structure. The complete integrated lens MIMO antenna (ILMA) measures just 22× 22× 20 mm3. Without the lens, the peak gain is limited to 6 dBi and 4.2 dBi at 28 GHz and 38 GHz, respectively. With the lens, gain improves to 10.5 dBi at 28 GHz and 9 dBi at 38 GHz. The antenna also achieves outstanding isolation, over 25 dB at 28 GHz and 30 dB at 38 GHz, with an envelope correlation coefficient (ECC) below 0.02 and diversity gain (DG) exceeding 9.9 dB across both bands. Link budget analysis confirms reliable communication up to 220 m at 28 GHz and 112 m at 38 GHz with 30 dBm transmit power. A fabricated prototype validates simulation results, showing strong agreement in S-parameters, isolation, gain, and radiation patterns. Compared to state-of-the-art designs, the proposed antenna offers superior gain, enhanced isolation, compact size, and cost-effective fabrication, making it well-suited for mmWave 5G NR bands such as n257, n260, and n261.