In this paper, a microstrip patch antenna fed by a stripline probe is proposed. The antenna works in X-band, and the patch is square in shape with a width of 9.3 mm; the feeder is bent through the microstrip line to stripline structure, and the upper part forms an L-shaped probe structure. The bandwidth of VSWR ＜ 2 in X-band is about 16.30%, the gain in vertical direction is about 8.78dB, and the cross polarization ratio is about 33.20dB. On the basis of this antenna, a PIFA antenna with similar structure is designed. The antenna bandwidth is increased to 19.1%, and the vertical cross polarization ratio of the patch is about 45.3dB, which is increased by more than 10dB. In practical application, this kind of antenna is not easy to be interfered by other antennas because of its good polarization isolation.