An efficient coplanar waveguide CPW T-matched slot-loop patch antenna has been designed at 2.45 GHz. DGS is implemented to obtain the 3 ^rd harmonic rejection while the second harmonic resonance is obtained by varying the T match length. The proposed antenna is well suitable for wireless power transmission because no input low pass filter and no via-hole connections are required, resulting in a simpler structure. An electromagnetic simulation has been used to optimize the antenna. The simulated antenna exhibits 4.4 dB gain at 2.45 GHz operating frequency. The return losses at the 2 ^nd and 3 ^rd harmonic frequencies are -1.2 dB and -1.6 dB respectively.