Abstract-A rectangular patch antenna with two circular apertures, a defected ground structure (DGS), and a shorting post is proposed in this paper. The novel structure can reduce the radar cross section (RCS) of the antenna at its operating frequency. At the same time, the return loss of the proposed antenna is maintained, and the RCSs of the patch antenna at the frequencies outside the operating band are also reduced. The proposed antenna is simulated by using high frequency electromagnetic simulation software. The peak of RCSs is reduced about 7 dB and the broadband RCSs are below −30 dB from 2 to 8 GHz. This result is useful for low-RCS antenna application.