This paper presents a novel wideband circularly polarized CPW-fed printed monopole antenna for CubeSat applications. An AMC reflector with 5×5-unit cells is used to increase antenna gain. The overall size of the antenna is 0.48λ0×0.48λ0×0.042λ0 at the operating frequency of 8GHz. The proposed printed monopole antenna provides a wide impedance bandwidth and a wide 3dB axial ratio bandwidth. When comparing our proposed antenna to all designs listed in Table II, it is evident that the proposed printed monopole antenna offers several advantages. Firstly, it exhibits higher gain and a wider 3dB axial ratio bandwidth (ARBW) while maintaining a smaller physical size. More specifically, the measured results show a wide -10 dB impedance bandwidth of 97.5% (6.1-13.9 GHz), and a wide measured 3dB axial ratio bandwidth of 98.75% (5.1 -13 GHz) and total measured gain of 7.3 dBi at 8 GHz.INDEX TERMS Artificial Magnetic Conductor (AMC), circular polarization, wideband, printed dipole.