Design guidance of a circularly polarized bowtie antenna for ISM bands

Abstract

This article presents the design steps of a planar circularly polarized (CP) bowtie-shaped antenna for 2.4–2.5 GHz industry, science, and medicine band. Using these design steps, an antenna model is developed. The antenna design is extensively described, simulated, measured, and analyzed. The antenna is simulated using the HFSS software and produced by laser etching of copper on a low-cost Taconic RF-35 substrate. The presented method of this design is easy to fabricate and is tunable to different frequencies. The produced CP planar antenna has a size of 55 × 55 × 0.25 mm3, a measured axial ratio bandwidth ranging from 2.33 to 2.49 GHz, and a measured peak gain of 3.21 dBiC. The produced antenna is fully planar, compatible with the printing process and thus suitable for Internet of Things applications.