3-D-Printed Encapsulated Dielectric Resonator Antennas With Large Operation Frequency Ratio for Future Wireless Communications

Shared aperture antennas are versatile structures that can fulfill the demand for multi-band compact antennas in multi-standard emerging communication systems. However, the requirement of operation at widely separated frequency bands, such as sub-6-GHz band and mm-wave band in 5G, poses a challenge. This paper introduces a novel Encapsulated Dielectric Resonator Antennas (E-DRAs) designed for operation at sub-6-GHz and mm-wave bands for 5G and beyond applications. The DRA part of the antenna consists of an array of small cylindrical DRAs (cDRA) encapsulated in a larger cylinder. At mm-wave band, the small cDRAs are radiating elements while the larger cylinder acts as a lens to enhance the gain and provide beam switching at discrete angles by switching the feed between the small cDRAs. At sub-6-GHz band, the large cylinder is the main radiator. The antenna is realized with a 3D printing process using two distinct ABS materials with different infills. Measurements of the fabricated antenna show a maximum gain of 7.8 dBi at 3.35 GHz and 19.7 dBi at 27 GHz. The measured bandwidth is 20.2% centered at 3.45 GHz and 28.7% centered at 28.5 GHz. The array of small cDRAs with five elements enables beam switching within ±30°.