A 3D-printed Encapsulated Dual Wide-Band Dielectric Resonator Antenna with Beam Switching Capability

This paper presents the concept of encapsulated dielectric resonator antennas (E-DRAs). In E-DRAs, smaller-sized DRAs with a specific permittivity is embedded inside a larger DRA with a lower permittivity allowing for simultaneous efficient radiation at two widely separated and widely covered frequency bands. In this work, the proposed E-DRAs cover both the sub-6-GHz band (with a large size DRA) and mm-wave band (with smaller sized DRAs) for 5G and beyond applications. The proposed design of the dual wide-band E-DRAs is fabricated using the fused filament fabrication (FFF) 3D printing process. At mm-wave bands, small cylindrical DRAs (cDRAs) are the radiating elements, and a larger cDRA in conjunction with a dielectric lens (DL) is used to achieve high gain radiation at such high bands. An array of 5 elements is used in a switched mode fashion to add switching beam capability to the antenna at the mm-wave band. Employing 3D printing reduces the fabrication time and cost and enables precise control of the dielectric constant of the DRAs. Measurement results show a maximum gain of 7.2 dBi at 3.2 GHz and 18 dBi at 31.5 GHz. The measured efficiency is more than 95% and 80% at sub-6-GHz and mm-wave bands, respectively. At the sub-6-GHz band, the measured 10-dB return loss bandwidth is 33% (centered at 3.6 GHz). At the mm-wave frequency band, the measured 10-dB return loss bandwidth is 27% (centered at 30.5 GHz). The achieved bandwidths are the highest among previous works on dual-band antennas at sub-6-GHz and mm-wave bands.