A Multiband Multibeam Antenna for Sub-6 GHz and mm-Wave 5G Applications

This letter first presents a concept of a dual-band antenna with a very large frequency ratio, which can be suitable for integrated 4G/millimeter (mm)-wave fifth-generation (5G) and beyond 5G applications for Internet of Things devices. The antenna is based on a tapered slot, which simultaneously works as a resonant open-ended slot at low frequency and a high-gain Vivaldi antenna at high frequency. The impedance bandwidth is improved by modifying the slot shape, i.e., creating multisections within the slot. Based on this approach, a multibeam antenna (gain of 10 dBi) at an mm-wave frequency which also covers multibands at lower frequency extending from 2.5 to 6 GHz is designed. The design is validated numerically and experimentally in terms of return loss, radiation efficiency, gain, total scan pattern, and coverage efficiency.