3-D-Printed Wideband High-Efficiency Dual-Frequency Antenna for Vehicular Communications

A three-dimensional (3-D)-printed dual-fed dual-frequency dielectric antenna is investigated for the vehicular communications. It combines a dielectric resonator (DR) antenna (DRA) and a dielectric lens antenna (DLA) for the low and high frequency bands, respectively. Both of the antenna parts share the same dielectric body that has three different effective dielectric constants. The DRA is excited by a vertical conducting adhesive strip on its side wall, whereas the DLA is fed by a separate embedded slot-coupled cylindrical DRA. To verify the idea, a dual-frequency dielectric antenna operating at S- and X-bands is designed and fabricated with a 3-D printer. The S-parameters, radiation patterns, antenna gains, and antenna efficiencies of the two antenna parts are measured, and reasonable agreement between the measured and simulated results is found. The prototype has wide measured S- and X-band 10-dB impedance bandwidths of 40.2% and 19.5%, respectively. Also, its measured isolation between the two ports is desirably over 40 dB across the two bands. The measured peak antenna gains are given by 5.8 and 12.0 dBi in S- and X-bands, which are suitable for short-distance vehicle-to-basestation and long-distance vehicle-to-satellite communications, respectively.