Low-Profile Aperture-Coupled Patch Antenna Array for CubeSat Applications

This paper presents the design, simulation, and measurement results of a dual aperture-coupled microstripline-fed antenna array with circular polarization at the C-band for small satellites applications. The antenna array was designed at a center frequency of 5.5 GHz, and it has a two-port isolation bandwidth of 25 MHz above 20 dB while the axial ratio is below 1 dB. The main objective is to produce a four-patch antenna array to be mounted on CubeSat deployable wings along with a layer of solar panels, maximizing the usable space and obtaining a better link budget for a standardized Cubesat of 10 cm × 10 cm × 10 cm. The orthogonal feedlines' isolation between Tx/Rx signals and a minimization of the multi-layer design provide a lower profile approach considering the state-of-the-art. The significant thickness reduction combined with a new perspective of having both deployable wings transmitting and receiving signals lead to a notable improvement of the overall system. This work is relevant due to the demand for high-performance antenna systems that may expand the capabilities of CubeSats, considering the importance of using an antenna array instead of a single element approach.