Polarization reconfigurable antennas have received considerable interest since they are useful for many applications such as polarization diversity, frequency reuse, and sensor systems. In this paper, a novel polarization switchable semi-loop antenna is presented. Polarization of the proposed antenna design can be switched to vertical polarization or horizontal polarization. The proposed antenna can be printed on a printed circuit board and utilized a CPW fed to ACPS structure to feed our antenna. This antenna design has a bias circuit to control two PIN diodes. When diode 1 is in the ON state and diode 2 is in the OFF state it is used to produce even mode of the CPW, and another one is when diode 1 is in the OFF state and diode 2 is in the ON state, which is coupled to CPW using ACPS, produces odd mode of the CPW. By exciting even mode or odd mode of the CPW, the proposed antenna can generate vertical polarization or horizontal polarization, respectively. Compared to the polarization switchable slot antennas found in the literature, the proposed design has a relatively compact size and has the advantages that the antenna mechanism and antenna performance will not be changed as the size of the ground plane changed. Also, resonant frequencies of the two orthogonal polarization can be easily adjusted. This design can be realized at the edge of the circuit board, making it more suitable for practical applications. The center frequency of the vertical polarization and horizontal polarization are both 2.4 GHz and the −10 dB reflection coefficient bandwidth of the vertical polarization and horizontal polarization both are over than 4.56 %, respectively. Antenna parameters such as reflection coefficient, isolation between two input ports, antenna gain, and radiation patterns are also measured to validate the proposed design.