Abstract: A satellite microstrip antenna with dual-circularly polarized and low passive intermodulation (PIM) performance is proposed. Based on the 3 dB coupler, the antenna with dual-circularly polarized performance for satellite T-R community application at S-band is obtained. In order to meet the space antenna′s strict requirements on processing technology, operating environment and PIM control, an air microstrip coupling feed network with media support is designed, which leads to an enhanced engineering feasibility and a low risk of PIM. The measured results show that the compact antenna has a good electrical performance, namely, at the T-R frequency the VSWR, axial ratio and isolation of the two circularly polarized ports are better than 1.2 dB,1.0 dB and -20 dB respectively. Meanwhile, the measured PIM value is below -130 dBm @ 10 W×2, 9th order.