Broadband Sinuous Antenna Design for 3U/6U CubeSat Applications

This paper presents the design and simulation of a broadband spiral antenna tailored for CubeSat applications operating in the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2-6 \text{GHz}$</tex> frequency range. The antenna is optimized for both 3 U and 6 U platforms, addressing the stringent size, weight, and power (SWaP) constraints typical of small satellite missions. A four-arm spiral configuration was employed to achieve wideband circular polarization, providing consistent gain and radiation characteristics across the operational band. The antenna structure, with compact physical dimensions of 41.01 mm in diameter and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{3 0. 2 0 ~ m m}$</tex> in height, was simulated using fullwave 3D electromagnetic solvers. The reflection coefficient (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$S_{11}$</tex>) remains below -10 dB over the entire band, indicating excellent impedance matching. Radiation patterns demonstrate stable main lobes and peak gains reaching 10.3 dBi at 6 GHz. The design further supports mechanical robustness and potential foldability, ensuring compatibility with CubeSat deployment mechanisms. These results validate the antenna's suitability for high-data-rate, polarization-diverse CubeSat communication and remote sensing missions.