This letter presents a novel design of circularly polarized (CP) antenna fed by a coplanar waveguide (CPW) working at 2.45/5.8 GHz. The physical dimension is 98 × 98 × 1 mm³ Circular polarization is obtained by the coupling between two T-shaped strips. The L-shaped strip is intended to improve impedance matching at the right lower corner whereas the horizontal L-shaped stub added to the upper right corner is to improve CP performance at 5.8 GHz. The simulated -10 dB reflection coefficient bandwidths of the proposed antenna are 14.29% and 13.62%, while the corresponding simulated axial-ratio (AR) bandwidths are 5% and 12.41%.