Harmonics suppression circular polarization elliptical shape microstrip patch antenna

This paper proposed a new design of a 2.45 GHz harmonic suppression circularly polarized microstrip patch antenna. The purpose of harmonic suppression antenna is to eliminate the using of harmonic filter circuit in a rectenna system as well as for the others active integrated antenna (AIA) applications. By introducing a defected ground structure (DGS) technique with a back-to-back U shape slot, the magnitude of the return loss at the harmonic frequencies are suppressed successfully. The patch antenna is designed on an FR4 substrate with ε
_r
=4.7 and a thickness of 1.6 mm have -28dB return loss at 2.45GHz and suppress the second and third harmonic up to -0.8dB and -1.8dB respectively.