Design approach to a planar bisensing circularly polarized (CP) antenna is presented. The antenna is composed of a circular sector magnetic dipole and two concentric annular electric dipoles. At first, the flared angle, radius of the circular sector magnetic dipole, and the feed positions of electric dipole are determined by the phase difference condition for bisensing CP radiations. Then, the arc length of concentric annular electric dipoles is determined. Finally, a concentric annular parasitic element is properly employed to compensate the phase and amplitude difference. In these ways, bisensing CP antenna with the main beam in parallel to its plane can be realized by using a simple planar configuration with only a few design parameters. As experimentally validated, the proposed antenna exhibits a nearly perfect bisensing CP characteristic at 2.50 GHz band.