Dual-Polarized Highly Folded Bowtie Antenna With Slotted Self-Grounded Structure for Sub-6 GHz 5G Applications

Abstract

In this communication, a novel dual-polarized highly folded self-grounded Bowtie antenna that is excited through I-shaped slots is proposed for applications in sub-6 GHz 5G multiple-input-multipleoutput (MIMO) antenna systems. The antenna consists of two pairs of folded radiation petals whose base is embedded in a double layer of FR-4 substrate with a common ground-plane which is sandwiched between the two substrate layers. The ground-plane is defected with two I-shaped slots located under the radiation elements. Each pair of radiation elements are excited through a microstrip line on the top layer with RF signal that is 180º out of phase with respect to each other. The RF signal is coupled to the pair of feedlines on the top layer through the I-shaped slots from the two microstrip feedlines on the underside of the second substrate. The proposed feed mechanism gets rid of the otherwise bulky balun. The Bowtie antenna is a compact solution with dimensions of 32 × 32 × 33.8 mm3.Measured results have verified that the antenna operates over a frequency range of 3.1–5 GHz and exhibits an average gain and antenna efficiency in the vertical and horizontal polarizations of 7.5 dBi and 82.6%, respectively.