In this work, planar circular-polarized (CP) antenna operating at 2.40–2.45 GHz is presented. The developed antenna is suitable for the installation on a Nanosatellite or CubeSat, which are usually considered lightweight satellites (below 10 kg), and used for the different observation purposes. The following requirements for the antenna design are considered: operation in S-band (2–4 GHz), circular polarization, and 10 × 10cm ground platform for the antenna installation. Developed patch antenna is theoretically studied using high frequency electromagnetic field simulation software, then it is manufactured, and a set of validation measurements is performed. The radiation characteristics, matching and losses are presented. The simulated and measured results correspond well to each other and fit the requirements. The S11 of the antenna is below -—6 dB in the desired frequency range and the simulated axial ratio values vary from 3 to 5.8 dB. The minimum measured axial ratio is 1.5 dB at 2.35 GHz. The results indicate that this antenna could be a good candidate for the installation on a nano-satellite chassis. © Springer Nature Switzerland AG 2018.