High Gain Dielectric Conical Horn Backed Dielectric Resonator MIMO Antenna with High Isolation for millimeter-Wave Band Applications

This paper presents a 3D-printed dielectric conical horn cavity (3D-PDCH) backed antenna, fabricated using additive manufacturing technology. The inner wall of the horn cavity is coated with copper tape as a cost-effective solution to achieve high gain antenna at the millimeter-wave (mm-Wave) band (26–32 GHz) for 5G applications. The horn cavity is fed by a dielectric resonator antenna (DRA) based MIMO system, which consists of four orthogonally placed cylindrical DRA circular arrays excited by an aperture-coupled feed line. To enhance isolation, metallic vias are introduced into the dielectric arms of the circular arrays. These vias interact with the electromagnetic fields to control their distribution and improve inter-element isolation (>20 dB). Moreover, the gain is improved by using a low-cost 3D-PDCH, which shapes the phase front of the radiated wave, minimizing phase errors and side lobes for a highly directive beam. With 3D-PDCH loading, the gain is enhanced by more than 200% in the desired band, with a realized peak gain of 22.3 dB at 27.5 GHz. The achieved 3-dB gain bandwidth (GBW) and fractional bandwidth (FBW) are 35.6% and 20.6%, respectively. The total efficiency is more than 80% with MIMO performance parameters (ECC <0.02 and ME ≈ 0.5 dB) in the desired band ensures its application in the mm-Wave band. To demonstrate the idea, the antenna is designed, fabricated, and measured at the mm-Wave band.