Abstract: The paper aims at the design of dual frequency and dual circular polarization antenna. Dual frequency covering can be achieved with a single patch using a relatively thick low dielectric constant substrate. Coupling apertures are used to realize dual circular polarization. The results simulated by Ansoft HFSS 8.0 and the measured data are presented. The antenna has been used in the terminal of ChuangXin No.1 microsatellite.