Study of Planar Wideband mm-Wave Bowtie Antennas Over PCB Ground Plane

This paper presents a bowtie antenna structure integrated on PCB, where on the other side of the substrate is the antenna itself, and on the other side is a conductive ground plane. Three different cases are studied with simulations and measurements in terms of -10 dB impedance matching within 24-40 GHz bandwidth, depending on studied antenna structure. These three cases are linearly polarized single-ended bowtie, linearly polarized differentially fed bowtie, and differentially fed dual-polarized bowtie antenna. All antenna structures are on the ground plane of size 10 mm x 10 mm for easier comparison. Manufactured prototype antennas are measured and simulated with a 50 Ω coaxial feed. Simulated polarization properties and 3D radiation patterns of the dual-polarized bowtie are presented at 28 GHz and 34 GHz, which both shows 95% simulated total efficiency. Over the studied frequency range, the simulated total efficiency is better than 50%.