Design and Implementation of Circularly Polarized Antenna for CubeSat Applications

This paper presents the design and implementation of a circularly polarized antenna optimized for CubeSat applications, specifically targeting the 2.4 GHz frequency commonly used in spaceborne communication systems. The proposed antenna is based on a planar rectangular patch configuration, featuring a microstrip planar patch attached to a coaxial SMA connector, and a second layer with a resonator and cavity model patch. The design methodology involves detailed calculations of the patch dimensions, effective permittivity, and matching impedance for a coaxial input of 50 Ohms. The truncated method is employed to achieve circular polarization, creating two orthogonal modes with a 90-degree phase difference by truncating the patch corners at 45 degrees. Parametric studies assess the impact of ground width, the gap between the resonator ring and main patch, and the gap between the top and bottom layers on the antenna's reflection coefficient (S11). The results indicate that a ground width of 46 mm and a 20 mm gap between the layers provide optimal impedance matching. The antenna's design is validated through simulation and practical implementation, demonstrating its effectiveness for CubeSat communication systems by achieving enhanced efficiency, reduced reflection, and improved overall performance.