A Double Layer Miniaturized Circularly Polarized Antenna for Millimeter-Wave Application

In this paper, a double-layer patch antenna for 5G millimeter-wave applications is designed and demonstrated. The antenna’s geometry is based on a microstrip patch antenna, with the ends truncated along one of the diagonals to shape the design. The antenna features a cross-slot aperture on the bottom patch and two open-ring structures on the top layer, and is fabricated using a high dielectric constant substrate, resulting in a compact design with a small size of only 2.08 mm. The simulated impedance bandwidth is approximately 11.43% (ranging from 29.7 GHz to 33.3 GHz). The simulated 3-dB axial ratio (AR) bandwidth is about 5.5% (ranging from 29.5 GHz to 31.16 GHz), with an in-band gain exceeding 5.0 dB.